Leases - Components of Lease Cost (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 8,084
Short-term lease cost	233
Sublease income	(722)
Total lease costs	7,595
Cash paid for amounts included in the measurement of lease liabilities	$ 8,552
Weighted-average remaining lease term (years)	5 years 9 months 18 days
Weighted-average discount rate	4.23%
Cash paid for amounts included in the measurement of lease liabilities related to interest	$ 1,300