Net Deferred Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current deferred income taxes:
Inventories	$ 5,968	$ 6,618
Accrued expenses	73,171	60,100
Derivative instruments	(1,474)	651
Total current	77,665	67,369
Noncurrent net deferred income taxes:
Cost in excess of net assets of business acquired	2,139	(1,973)
Property and equipment	(21,296)	(20,786)
Compensation payable in common stock	31,274	30,119
Net unrealized gains in other comprehensive income	(1,516)	(8,297)
Total noncurrent	10,601	(937)
Total	$ 88,266	$ 66,432