Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operating lease cost
Operating lease cost	$ 2,347	$ 6,940
Finance lease cost
Amortization of right-of-use assets	75	225
Interest on lease liabilities	16	54
Total Finance lease cost	91	279
Variable lease cost	614	1,991
Total lease cost	$ 3,052	$ 9,210