Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 4,253	$ 12,650
Sublease (income)	(37)	(328)
Net lease cost	$ 4,216	$ 12,322