Reconciliation Between Statutory Federal Income Tax Rate and Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Reconciliation of Federal Statutory Tax Rates
U.S. Statutory Tax Rate	35.00%		35.00%		35.00%
Increase (Decrease) Due to State and Local Taxes	8.40%		13.10%		7.10%
Rate Benefits as a Limited Liability Company/Flow Through	(6.90%)		(5.70%)		(10.20%)
Foreign Taxes	2.20%		4.30%		0.10%
Non-Deductible Expenses	9.40%	[1]	17.10%	[1]	12.20%	[1]
Valuation Allowances	(2.00%)		(0.90%)		0.70%
Other Adjustments	(2.20%)		(1.00%)		(0.30%)
Effective Income Tax Rate	43.90%		61.90%		44.60%

[1] Primarily related to non-deductible share-based compensation expense.