Leases - Lease Expense Components (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 9,462	$ 18,980
Short-term lease cost	582	845
Variable lease cost	933	1,779
Less: sublease income	(1,115)	(2,223)
Total lease cost, net	9,862	19,381
Cash paid for operating leases	$ 10,884	$ 21,238
Weighted-average remaining term (in years) - operating leases	6 years 2 months 19 days	6 years 2 months 19 days
Weighted-average discount rate - operating leases	3.19%	3.19%