New Accounting Standards - Summary of Adjustments to Quarterly Data Resulting from Adoption of New Standard in Statements of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
New Accounting Pronouncement Early Adoption [Line Items]
Income tax benefit	$ 112,395	$ (41,976)
Net income (loss)	$ 170,111	$ (93,772)
Basic earnings per share	$ 0.69	$ (0.56)
Diluted earnings per share	$ 0.69	$ (0.56)
Accounting Standards Update 2016-09
New Accounting Pronouncement Early Adoption [Line Items]
Income tax benefit		$ (41,976)
Net income (loss)		$ (93,772)
Basic earnings per share		$ (0.56)
Diluted earnings per share		$ (0.56)
Accounting Standards Update 2016-09 | As Reported
New Accounting Pronouncement Early Adoption [Line Items]
Income tax benefit		$ (44,038)
Net income (loss)		$ (91,710)
Basic earnings per share		$ (0.55)
Diluted earnings per share		$ (0.55)