Income Taxes - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Taxes Payable	$ 20,304	$ 5,159
Payment to the LP Unit holders of the cash tax savings, percent		85.00%
Retained percent of tax benefits		15.00%
Deferred Tax Assets-Non-Current	229,449	186,689
Amounts Due Pursuant to Tax Receivable Agreements	165,350	137,448
Increase to Additional Paid-In-Capital	15,022	2,545
Additionally, increase in net deferred tax assets, before valuation allowance	1,494
Increase in deferred tax assets associated with changes in Accumulated Other Comprehensive Income (Loss)	(1,981)	3,046
Unrecognized tax benefits that would affect the effective tax rate	98	0
Unrecognized tax benefits accrued interest	10	136
Unrecognized tax benefits accrued penalties	6	0
Unrecognized tax benefits, recognized liability for penalties	32	255
Unrecognized tax benefits, recognized liability for interest	17	387
Recognized tax benefits, penalties	(228)	(398)
Recognized tax benefits, interest	(375)	(456)
UNITED KINGDOM
Income Taxes [Line Items]
Net operating loss and tax credit carryforwards	10,301
MEXICO
Income Taxes [Line Items]
Net operating loss and tax credit carryforwards	1,139
Exchange of LP Units
Income Taxes [Line Items]
Common Stock, shares issued	3,091,000
Deferred Tax Assets-Non-Current	38,974	0
Amounts Due Pursuant to Tax Receivable Agreements	33,128	0
Increase to Additional Paid-In-Capital	5,846	0
Foreign Subsidiaries
Income Taxes [Line Items]
Undistributed earnings of foreign subsidiaries	2,660
Unrecognized net deferred tax liability	$ 703