Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jan. 01, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Provision (benefit) for income taxes	$ (18,202)	$ 57,354	$ 131,221	$ (75,556)	$ 130,311
Adjustments for New Accounting Principle, Early Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cumulative effect of change in retained earnings						$ (7,000)
Provision (benefit) for income taxes	$ (9,000)			$ (17,000)