Summary of Significant Accounting Policies - Schedule Related to Adoption of Accounting Standards (Share-Based Compensation and Restricted Cash and Cash Equivalents) (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities	$ 133,660	$ 112,464
Net cash used in investing activities	(86,683)	(104,210)
Net cash provided by financing activities	(32,162)	8,720
Net increase in cash and cash equivalents and restricted cash	14,815	16,974
Cash and cash equivalents and restricted cash, beginning of period	130,907	98,420
Cash and cash equivalents and restricted cash, end of period	$ 145,722	115,394
As Reported [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by operating activities		114,024
Net cash used in investing activities		(106,710)
Net cash provided by financing activities		14,204
Net increase in cash and cash equivalents and restricted cash		21,518
Cash and cash equivalents and restricted cash, beginning of period		23,036
Cash and cash equivalents and restricted cash, end of period		$ 44,544