Organization and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 7.5% Senior Notes due 2022	Dec. 31, 2012 Building
Schedule Of Significant Accounting Policies [Line Items]
Long-term debt	$ 914,126	$ 620,000	$ 300,000
Senior convertible note, maturity year			2017
Senior convertible note, stated interest rate			1.75%
Estimated useful life of Building				39 years