Compensation and Benefit Plans (Stock Options) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Stock Options
Outstanding, at the beginning of period (in options)	3,344,611
Granted (in options)	660,222
Expired (in options)	(112,129)
Transferred to affiliates (in options)	(270,312)
Forfeited (in options)	(41,094)
Exercised (in options)	(881,064)
Outstanding, at the end of period (in options)	2,700,234
Vested and expected to vest, at the end of period (in options)	2,586,910
Exercisable, at the end of period (in options)	1,286,055
Weighted-Average Exercise Price
Outstanding, at the beginning of period (in dollars per option)	$ 34.05
Granted (in dollars per option)	$ 43.16
Expired (in dollars per option)	$ 47.39
Transferred to affiliates (in dollars per option)	$ 33.13
Forfeited (in dollars per option)	$ 39.88
Exercised (in dollars per option)	$ 26.39
Outstanding, at the end of period (in dollars per option)	$ 38.23
Vested and expected to vest, at the end of period (in dollars per option)	$ 38.23
Exercisable, at the end of period (in dollars per option)	$ 38.30
Weighted-Average Remaining Contractual Term (Years)
Outstanding, at the end of period	6 years 2 months 27 days
Vested and expected to vest, at the end of period	6 years 1 month 28 days
Exercisable, at the end of period	4 years 2 months 19 days
Aggregate Intrinsic Value
Vested and expected to vest, at the end of period	$ 20
Exercisable, at the end of period	10
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
General expiration period after grant date	10 years
Vesting period	4 years
Number of years from the grant of options during which dividend equivalents accrue	5 years
Aggregate Intrinsic Value
Unrecognized compensation cost	$ 4.0
Weighted-average period, recognition of unrecognized compensation cost (in years)	2 years