| **Leases**            | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
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| **Leases [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Leases                | LEASES We lease our offices and other property through operating leases.  Rental expense is charged to operations as incurred.  For 2012, 2011 and 2010, total rental expense for operating leases was $16 million, $15 million and $16 million, respectively.  At December 31, 2012, minimum payments for operating leases having initial or remaining non-cancelable terms in excess of one year were as follows: (Millions of dollars) 2013$14201413201512201610201710Thereafter36Total$95   |

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| - Definition
Tabular disclosure of a lessee's leasing arrangements including: (1) the basis on which contingent rental payments are determined, (2) the existence and terms of renewal or purchase options and escalation clauses, (3) restrictions imposed by lease arrangements, such as those concerning dividends, additional debt, and further leasing, (4) rent holidays, rent concessions, or leasehold improvement incentives and unusual provisions or conditions.  Disclosure may also include the specific period used to amortize material leasehold improvements made at the inception of the lease or during the lease term. Additionally, for operating leases having initial or remaining noncancelable lease terms in excess of one year: (a) future minimum rental payments required as of the date of the latest balance sheet presented, in the aggregate and for each of the five succeeding fiscal years, (b) the total of minimum rentals to be received in the future under noncancelable subleases as of the date of the latest balance sheet presented, and (c) for all operating leases, rental expense for each period for which an income statement is presented, with separate amounts for minimum rentals, contingent rentals, and sublease rentals. Rental payments under leases with terms of a month or less that were not renewed need not be included.
+ References
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