to determine stock-based compensation expense , the grant date fair value is applied to the options granted with a reduction for estimated forfeitures . we recognize compensation expense for stock options on a straight-line basis over the specified vesting period . at december 31 , 2013 and 2012 , options for 10204000 and 12759000 shares of common stock were exercisable at a weighted-average price of $ 89.46 and $ 90.86 , respectively . the total intrinsic value of options exercised during 2014 , 2013 and 2012 was $ 90 million , $ 86 million and $ 37 million , respectively . cash received from option exercises under all incentive plans for 2014 , 2013 and 2012 was approximately $ 215 million , $ 208 million and $ 118 million , respectively . the tax benefit realized from option exercises under all incentive plans for 2014 , 2013 and 2012 was approximately $ 33 million , $ 31 million and $ 14 million , respectively . shares of common stock available during the next year for the granting of options and other awards under the incentive plans were 17997353 at december 31 , 2014 . total shares of pnc common stock authorized for future issuance under equity compensation plans totaled 19017057 shares at december 31 , 2014 , which includes shares available for issuance under the incentive plans and the employee stock purchase plan ( espp ) as described below . during 2014 , we issued approximately 2.4 million shares from treasury stock in connection with stock option exercise activity . as with past exercise activity , we currently intend to utilize primarily treasury stock for any future stock option exercises . awards granted to non-employee directors in 2014 , 2013 and 2012 include 21490 , 27076 and 25620 deferred stock units , respectively , awarded under the outside directors deferred stock unit plan . a deferred stock unit is a phantom share of our common stock , which is accounted for as a liability until such awards are paid to the participants in cash . as there are no vesting or service requirements on these awards , total compensation expense is recognized in full for these awards on the date of grant . incentive/performance unit share awards and restricted stock/share unit awards the fair value of nonvested incentive/performance unit share awards and restricted stock/share unit awards is initially determined based on prices not less than the market value of our common stock on the date of grant . the value of certain incentive/performance unit share awards is subsequently remeasured based on the achievement of one or more financial and other performance goals . the personnel and compensation committee ( 201cp&cc 201d ) of the board of directors approves the final award payout with respect to certain incentive/performance unit share awards . these awards have either a three-year or a four-year performance period and are payable in either stock or a combination of stock and cash . restricted stock/share unit awards have various vesting periods generally ranging from 3 years to 5 years . beginning in 2013 , we incorporated several enhanced risk- related performance changes to certain long-term incentive compensation programs . in addition to achieving certain financial performance metrics on both an absolute basis and relative to our peers , final payout amounts will be subject to reduction if pnc fails to meet certain risk-related performance metrics as specified in the award agreements . however , the p&cc has the discretion to waive any or all of this reduction under certain circumstances . the weighted-average grant date fair value of incentive/ performance unit share awards and restricted stock/unit awards granted in 2014 , 2013 and 2012 was $ 80.79 , $ 64.77 and $ 60.68 per share , respectively . the total fair value of incentive/performance unit share and restricted stock/unit awards vested during 2014 , 2013 and 2012 was approximately $ 119 million , $ 63 million and $ 55 million , respectively . we recognize compensation expense for such awards ratably over the corresponding vesting and/or performance periods for each type of program . table 121 : nonvested incentive/performance unit share awards and restricted stock/share unit awards 2013 rollforward shares in thousands nonvested incentive/ performance unit shares weighted- average grant date fair value nonvested restricted stock/ weighted- average grant date fair value .
in shares in thousands , for the non-vested incentive/ performance unit shares , what was the change in balance between december 31 2013 and december 31 2014?
the pnc financial services group , inc . 2013 form 10-k 185 .