Leases - Supplemental Cash Flow Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases
Cash paid for operating lease liabilities	$ 10,116
Right-of-use assets obtained in exchange for new operating lease liabilities	1,040
Cash received from sublease income	$ 2,061
Weighted-average remaining lease term of operating leases	7 years 4 months 2 days
Weighted-average discount rate of operating leases	6.91%