Long-term Incentive Compensation Plans (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Long-term incentive compensation plans
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 587,131,000	$ 587,131,000	$ 0	$ 0
Awards vested ratably (in years)		4
Combined Incentive Compensation Plans [Member]
Long-term incentive compensation plans
Aggregate value awards under combined incentive plans		159,900,000	275,600,000	223,100,000
Deferred Compensation Arrangement with Individual, Compensation Expense		654,300,000	207,900,000	202,300,000
Incentive Compensation Plan [Member]
Long-term incentive compensation plans
One-time, non-cash deferred compensation charge		509,100,000
Wealth Accumulation Plan [Member]
Long-term incentive compensation plans
Percentage of award that can be allocated to units, maximum (in hundredths)	50.00%	50.00%
Aggregate value awards under combined incentive plans				16,500,000
Deferred Compensation Arrangement with Individual, Compensation Expense		25,500,000	8,500,000	9,500,000
One-time, non-cash deferred compensation charge		24,800,000
Commission Substitution Plan [Member]
Long-term incentive compensation plans
Deferred Compensation Arrangement with Individual, Compensation Expense		100,000	100,000	10,500,000
Awards vested ratably (in years)		3
Capital Accumulation Plan [Member]
Long-term incentive compensation plans
Deferred Compensation Arrangement with Individual, Compensation Expense		$ 900,000	$ 1,200,000	$ 1,400,000
Period of payment under deferred compensation arrangement (in years)		10