Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
New Accounting Pronouncement, Early Adoption [Line Items]
Restricted cash	$ 8,500
Increase to net cash provided by operating activities	85,769	$ 111,420
Increase to net cash used in financing activities	$ (38,736)	(93,291)
Accounting Standards Update 2016-09
New Accounting Pronouncement, Early Adoption [Line Items]
Increase to net cash provided by operating activities		6,339
Increase to net cash used in financing activities		$ 6,339
Accounting Standards Update 2016-09 | Retained Earnings
New Accounting Pronouncement, Early Adoption [Line Items]
Cumulative impact of adjustment to retained earnings			$ 800