Leases - Lease Expense and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lease cost
Operating lease cost	$ 5,989	$ 18,573
Finance lease cost:
Amortization of right-of-use assets	23	71
Interest on lease liabilities	33	98
Short-term lease cost	(10)	70
Sublease income	(97)	(289)
Total lease cost	5,938	18,523
Other information
(Gain)/loss on right-of-use asset impairment-Operating leases	0	2,551
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	5,279	16,626
Operating cash flows from finance leases	32	98
Financing cash flows from finance leases	32	94
Right-of-use assets obtained in exchange for new lease obligations:
Right-of-use assets obtained in exchange for lease obligations - operating leases	574	5,358
Right-of-use assets obtained in exchange for lease obligations - finance leases	$ 0	$ 0