| **Stock-based compensation plans**                                            | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        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| **Disclosure of Compensation Related Costs, Share-based Payments [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  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| Disclosure of Compensation Related Costs, Share-based Payments [Text Block]   | Stock-based compensation plans In February 2004, our shareholders approved the 2004 Performance Incentive Plan (“2004 Plan”), which  provides for the granting of stock options, restricted stock, restricted stock units, cash-settled restricted stock units and cash-settled performance shares to employees and non-employee directors and consultants. The awards granted under the 2004 Plan are established by our Board of Directors or committee thereof at the time of issuance. Options are awarded with an exercise price equal to the fair market value of our common stock on the date of grant and generally vest over a three year period. The stock options granted prior to December 2009 generally have a 10-year contractual life. Starting with the December 2009 option grants, the Company granted awards with a 7-year contractual life. Restricted stock is common stock that is subject to forfeiture or other restrictions that will lapse upon satisfaction of specified conditions.  Restricted stock units represent the right to receive shares of common stock in the future, with the right to future delivery of the shares subject to forfeiture or other restrictions that will lapse upon satisfaction of specified conditions. Awards of performance shares, which are based on cash-settled stock units, will be earned by comparing the Company's total shareholder return for a pre-determined period to the Company's percentile ranking when compared to its peer group. Awards of cash-settled restricted stock units and performance shares are classified as liabilities and are remeasured at each reporting date.The 2004 Plan replaced on a prospective basis, our 1994 Performance Incentive Plan, 1998 Supplemental Stock Plan, and 1998 Non-Employee Director Stock Option Plan (the "Prior Plans") such that all future grants will be granted under the 2004 Plan and any shares that are cancelled, expired, forfeited, settled in cash or otherwise terminated without a delivery of shares to the participant will become available for grant under the 2004 Plan.A total of 3,250,000 shares of common stock were originally reserved for awards under the 2004 Plan. In February 2010, an additional 2,500,000 shares were approved by the shareholders, which increased the total shares of common stock reserved for awards under the 2004 Plan to 5,750,000 shares. Shares subject to awards under the 2004 Plan and shares subject to awards under any Prior Plans that are cancelled, expired, forfeited, settled in cash, tendered to satisfy the purchase price of an award, withheld to satisfy tax obligations, or otherwise terminated without a delivery of shares to the participant become available for future awards under the 2004 Plan. As of October 31, 2011, 2,710,359 shares remain available for issuance under the 2004 Plan.The following plans were approved by our Board of Directors but were not approved and were not required to be approved by our stockholders: the Executive Stock Ownership Program (the “Ownership Program”) and the Non-Employee Directors Deferred Fee Plan (the “Deferred Fee Plan”). Ownership Program. In June 1997, our Board of Directors approved the terms of the Ownership Program, and has since amended it from time to time. In general, the Ownership Program requires all officers and senior managers to acquire, by direct purchase or through salary or annual bonus reduction, an ownership interest in the Company by acquiring a designated amount of our common stock at specified timelines. Participants are required to hold such stock for the entire period in which they are employed by the Company. Participants may defer their cash bonus into deferred share units (“DSUs”), which vest immediately. There were 27,671 DSUs outstanding as of October 31, 2011. Premium share units (“PSUs”) may also be awarded to participants who complete their ownership requirement on an accelerated basis. PSUs vest annually, pro rata over three years. There were 89,112 PSUs outstanding as of October 31, 2011. Each vested DSU and PSU will be settled by delivery of one share of common stock within 10 days after a participant's termination of employment or at such later date as required by Internal Revenue Code Section Rule 409A. Beginning in February 2004, PSU's and DSU's awarded under this program are issued under the 2004 Plan. Deferred Fee Plan. Under the Deferred Fee Plan, non-employee directors may elect to defer payment of all or a portion of their retainer fees and meeting fees in cash (with interest) or in stock units. Deferrals in the deferred stock account are valued as if each deferral was vested in NIC common stock as of the deferral date. As of October 31, 2011, 42,267 deferred shares were outstanding under the Deferred Fee Plan. The following summarizes stock option activity for the years ended October 31:  2011 2010 2009 Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price (in thousands)   (in thousands)   (in thousands)  Options outstanding, at beginning of year4,911 $33.81 5,917 $33.09 5,589 $34.60Granted1,069 60.32 599 38.71 951 22.66Exercised(1,440) 34.87 (1,147) 30.94 (456) 30.29Forfeited/expired(40) 47.06 (458) 38.14 (167) 31.81Options outstanding, at end of year4,500 39.65 4,911 33.81 5,917 33.09Options exercisable, at end of year3,064 $36.07 3,767 $34.67 5,023 $34.95The following table summarizes information about stock options outstanding at October 31, 2011: Options Outstanding  NumberOutstanding  WeightedAverageRemainingContractualLife  WeightedAverageExercisePrice   Aggregate Intrinsic ValueRange of Exercise Prices          (in thousands) (in years)   (in millions)$ 21.22 - $ 31.81 1,615 4.2 $24.98 $28$ 32.18 - $ 40.92 1,043 3.9 38.80 3$ 42.48 - $ 69.91 1,842 3.9 53.00 —The following table summarizes information about stock options exercisable at October 31, 2011: Options Exercisable  NumberOutstanding  WeightedAverageRemainingContractualLife  WeightedAverageExercisePrice   Aggregate Intrinsic ValueRange of Exercise Prices          (in thousands) (in years)   (in millions)$ 21.22 - $ 31.81 1,347 3.6 $25.45 $22$ 32.18 - $ 40.92 738 3.3 40.02 2$ 42.48 - $ 69.91 979 2.0 47.70 —The weighted average grant date fair value of options granted during the years ended October 31, 2011, 2010, and 2009 was $26.40, $18.00, and $10.35, respectively.  The total intrinsic value of stock options exercised during the years ended October 31, 2011, 2010, and 2009 was $38 million, $20 million, and $14 million, respectively. The fair value of each option grant was estimated on the grant date using the Black-Scholes option-pricing model with the following weighted average assumptions:   2011 2010 2009Risk-free interest rate 2.27% 2.72% 1.34%Dividend yield —% —% —%Expected volatility 46.80% 52.60% 47.30%Expected life in years 5.4 5.5 5.9The use of the Black-Scholes option-pricing model requires us to make certain estimates and assumptions. The risk-free interest rate utilized is the implied yield on U.S. Treasury zero-coupon issues with a remaining term equal to the expected term assumption on the grant date, rounded to the nearest half year. A dividend yield assumption of 0% is used for all grants based on the Company's history of not paying a dividend to any class of stock. Expected volatility is based on our historical stock prices and implied volatilities from traded options in our stock. The weighted average expected life in years for all grants as a group is then calculated for each year. We monitor share option exercise and employee termination patterns to estimate forfeiture rates. Restricted stock unit and cash-settled restricted stock unit activity for the year ended October 31, 2011 was as follows:  Share-Settled Restricted Stock Units Cash-Settled Restricted Stock Units  Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value  (in thousands)   (in thousands)  Nonvested at October 31, 2010 459 $45.21 275 $35.81Granted 43 53.72 225 59.25Vested (333) 50.98 (90) 35.81Forfeited (7) 46.75 (17) 46.53Nonvested at October 31, 2011 162 35.54 393 48.80The aggregate fair value of restricted stock units vested during the years ended October 31, 2011, 2010, and 2009 was $20 million, $9 million, and $9 million, respectively.During the year ended October 31, 2011, we awarded 149,620 cash-settled performance shares with a weighted average grant date fair value per share of $84.75. We estimated the fair value of each performance share granted on the date of grant using a Monte Carlo simulation that uses expected volatility and risk-free rate assumptions.  An expected volatility of 47.3% was used and was based on the implied volatility of traded call options in our stock and the historical volatility of our daily stock price.  A risk free rate of 2.03% was used and was based on the rate on zero-coupon government bonds with a term commensurate with the remaining performance period at grant date.There were no cash-settled performance shares granted during 2010 and 2009. No cash-settled performance shares vested during the year ended October 31, 2011.Total share-based compensation expense for the years ended October 31, 2011, 2010, and 2009 was $36 million, $24 million and $16 million respectively. As of October 31, 2011, there was $29 million of total unrecognized compensation expense related to non-vested share-based awards. The compensation expense is expected to be recognized over a weighted average period of 2 years.The Company received cash of $40 million, $30 million, and $13 million during the years ended October 31, 2011, 2010, and 2009, respectively, related to stock awards exercised. The Company used cash of $5 million during 2011 to settle cash-settled restricted stock units. The Company did not realize any tax benefit from stock awards exercised for 2011, 2010, or 2009. Redeemable Equity Securities. Our options contained provisions allowing for a cash settlement in the event of a change in control and when certain other conditions existed. Accordingly, the intrinsic value of these options was reflected as mezzanine equity. In the first quarter of 2009, we modified the terms of certain outstanding stock options classified as mezzanine equity. The modification, which required the consent of plan participants, eliminated the feature that allowed for cash settlement in the event of a change in control when certain other conditions existed. As a result, the value of the modified award is no longer required to be presented as mezzanine equity under the guidance on the classification and measurement of redeemable securities. The modification resulted in a reduction of $130 million of Redeemable equity securities and a corresponding increase to Additional paid in capital in 2009. As additional plan participants consent to the modification, exercise their stock options, or they expire, additional amounts will be reclassified from Redeemable equity securities to Additional paid in capital. |

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| - Definition
The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.
+ References
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