Summary of Significant Accounting Policies - Rollforward of Deferred Revenue (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Beginning Balance	$ (54,231)	$ (54,231)
Revenue recognized that was included in deferred revenue at the beginning of the period		38,832
Consideration received in advance of services performed net of revenue recognized in the current period		(50,861)
Other		1,877
Ending Balance	(47,611)	$ (57,763)
ASC 606
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Reclassification – adoption of ASC 606	2,276
ASC 606 | Deferred Revenue
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cumulative effect adjustments	$ 4,344