Commitments and Contingencies - Other Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash paid for amounts included in the measurement of lease liabilities
Cash paid for amounts included in the measurement of lease liabilities, operating cash flows from operating leases	$ 2,567	$ 2,600
Cash paid for amounts included in the measurement of lease liabilities, operating cash flows from finance leases	201	109
Cash paid for amounts included in the measurement of lease liabilities, financing cash flows from finance leases	3,060	2,159
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	20,395	1,117
Finance leases	$ 3,566	$ 99
Weighted average remaining lease term (years):
Weighted average remaining lease term (years), operating leases	5 years 6 months 18 days	3 years 10 months 20 days
Weighted average remaining lease term (years), finance leases	2 years 10 months 24 days	1 year 10 months 13 days
Weighted average discount rate:
Weighted average discount rate, operating leases	5.20%	4.10%
Weighted average discount rate, finance leases	4.30%	3.10%