Carrying Amounts and Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, Carrying Value	$ 271,512	$ 233,710	$ 90,565	$ 413,359
Notes receivable, Carrying Value	51,130	71,661
Restricted cash, Carrying Value	9,388	2,475
Notes payable, Carrying Value	(47,688)	(131,651)
Current portion of long-term debt	(2,336)	(21,199)
Long-term debt, Carrying Value	(336,631)	(329,496)
Quoted Prices in Active Markets for Identical Assets Level (1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value	271,512	233,710
Notes receivable, Fair Value Disclosure	51,130	71,661
Restricted cash, Fair Value	9,388	2,475
Notes payable, Fair Value	(47,688)	(131,651)
Current portion of long-term debt, Fair Value	(2,336)	(21,199)
Long-term debt, Fair Value	$ (355,731)	$ (325,596)