Operating Lease Right-of-Use Assets and Liabilities - Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Lease expense	$ 10,367	$ 28,488
Short-term and variable lease cost	241	332
Sublease income	(447)	(1,189)
Total lease cost for operating leases	$ 10,161	$ 27,631