Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2012	Dec. 31, 2014	Mar. 06, 2012
Building [Member]
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful life of building	39 years
1.75% Senior Convertible Notes due 2017 [Member]
Schedule Of Significant Accounting Policies [Line Items]
Aggregate principal amount of debt issued		$ 300,000,000		$ 300,000,000
Senior convertible note, stated interest rate	1.75%	1.75%	1.75%
Senior convertible note, maturity year		2017