Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease costs	$ 8,758	$ 28,357
Financing lease costs:
Amortization of right-of-use assets	180	657
Interest on lease liabilities	14	69
Total financing lease costs	194	726
Variable lease costs	1,091	3,277
Total lease costs	$ 10,043	$ 32,360