Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Foreign exchange gain (loss) recognized	$ (800)	$ 200		$ 800	$ 800
Income before income taxes	190,389	162,348	[1]	357,757	319,260	[1]
Provision for income taxes	59,402	46,095	[1]	103,077	91,917	[1]
Net income	$ 130,987	$ 116,253	[1]	$ 254,680	$ 227,343	[1],[2]
Earnings per share:
Basic earnings per share (in dollars per share)	$ 1.42	$ 1.25	[1]	$ 2.77	$ 2.46	[1]
Diluted earnings per share (in dollars per share)	$ 1.39	$ 1.22	[1]	$ 2.70	$ 2.39	[1]
Weighted average common shares outstanding:
Basic weighted average shares outstanding (in shares)	92,013	92,665	[1]	92,060	92,591	[1]
Diluted weighted average shares outstanding (in shares)	94,223	95,279	[1]	94,392	95,137	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities		$ 212,042		$ 179,004	$ 212,042	[2]
Net cash used in investing activities		(37,924)		(42,507)	(37,924)	[2]
Net cash provided by (used in) financing activities		(121,489)		(67,805)	(121,489)	[2]
Effect of foreign currency exchange rates on cash		(6,696)		20,868	(6,696)	[2]
Net increase in cash and cash equivalents		45,933		$ 89,560	45,933	[2]
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income before income taxes		162,348			319,260
Provision for income taxes		48,163			95,103
Net income		$ 114,185			$ 224,157
Earnings per share:
Basic earnings per share (in dollars per share)		$ 1.23			$ 2.42
Diluted earnings per share (in dollars per share)		$ 1.21			$ 2.37
Weighted average common shares outstanding:
Basic weighted average shares outstanding (in shares)		92,665			92,591
Diluted weighted average shares outstanding (in shares)		94,549			94,437
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities		$ 208,856
Net cash used in investing activities		(37,924)
Net cash provided by (used in) financing activities		(118,303)
Effect of foreign currency exchange rates on cash		(6,696)
Net increase in cash and cash equivalents		45,933
Accounting Standards Update 2016-09 | Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income before income taxes		0			$ 0
Provision for income taxes		(2,068)			(3,186)
Net income		$ 2,068			$ 3,186
Earnings per share:
Basic earnings per share (in dollars per share)		$ 0.02			$ 0.04
Diluted earnings per share (in dollars per share)		$ 0.01			$ 0.02
Weighted average common shares outstanding:
Basic weighted average shares outstanding (in shares)		0			0
Diluted weighted average shares outstanding (in shares)		729			700
Adjustments to reconcile net income to net cash provided by operating activities:
Net cash provided by operating activities		$ 3,186
Net cash used in investing activities		0
Net cash provided by (used in) financing activities		(3,186)
Effect of foreign currency exchange rates on cash		0
Net increase in cash and cash equivalents		$ 0

[1] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, to simplify several aspects of the accounting for share-based compensation, including the income tax consequences.

[2] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, to simplify several aspects of the accounting for share-based compensation, including the income tax consequences.