Stock Based Compensation Plans, Restricted stock activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2001
Nonvested stock [Roll forward]
Unvested, beginning balance (in shares)	44,877,000	37,727,000	30,304,000
Granted (in shares)	1,540,000	14,415,000	18,954,000
Vested (in shares)	(9,532,000)	(6,126,000)	(5,647,000)
Forfeited and canceled (in shares)	(1,666,000)	(1,139,000)	(5,884,000)
Unvested, ending balance (in shares)	35,219,000	44,877,000	37,727,000
Additional disclosures [Abstract]
Weighted-average grant price, unvested, beginning balance (in dollars per share)	$ 102.46	$ 99.43	$ 119.31
Weighted-average grant price, granted (in dollars per share)	$ 134.44	$ 109.62	$ 75.77
Weighted-average grant price, vested (in dollars per share)	$ 104.71	$ 102.27	$ 108.49
Weighted-average grant price, forfeited and canceled (in dollars per share)	$ 94.35	$ 93.92	$ 116.89
Weighted-average grant price, unvested, ending balance (in dollars per share)	$ 98.57	$ 102.46	$ 99.43
Series Z Incentive Units [Member]
Nonvested stock [Roll forward]
Unvested, beginning balance (in shares)	171,902,000	105,881,000	143,604,000
Granted (in shares)	46,500,000	108,000,000		200,000
Vested (in shares)	(44,520,000)	(37,629,000)	(37,723,000)
Forfeited and canceled (in shares)	(3,863,000)	(4,350,000)
Unvested, ending balance (in shares)	170,019,000	171,902,000	105,881,000
Additional disclosures [Abstract]
Weighted-average grant price, unvested, beginning balance (in dollars per share)	$ 54.15	$ 39.36	$ 39.36
Weighted-average grant price, unvested, ending balance (in dollars per share)	$ 55.69	$ 54.15	$ 39.36
Incentive units vested [Roll Forward]
Vested, beginning balance (in shares)	326,280,000	288,651,000	250,928,000
Vested, units granted (in shares)	0	0
Vested, units vested (in shares)	44,520,000	37,629,000	37,723,000
Vested, ending balance (in shares)	370,800,000	326,280,000	288,651,000
Aggregate intrinsic value, unvested, beginning balance	$ 20,400	$ 9,435	$ 11,505
Aggregate intrinsic value, unvested, ending balance	$ 17,232	$ 20,400	$ 9,435
Total outstanding incentive units [Abstract]
Total outstanding units, beginning balance (in shares)	498,182,000	394,532,000	394,532,000
Total outstanding units, granted (in shares)	46,500,000	108,000,000
Total outstanding units, vested (in shares)	0	0	0
Total outstanding units, cancelled (in shares)	(3,863,000)	(4,350,000)
Total outstanding units, ending balance (in shares)	540,819,000	498,182,000	394,532,000
Weighted-average remaining contractual life, beginning balance (in years)	11.2	8.2	9.2
Weighted-average remaining contractual life, ending balance (in years)	12.2	11.2	8.2