Leases - Lease Cost and Other Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Cash Flow, Operating Activities, Lessee [Abstract]
Cash paid for operating lease liabilities	$ 16,728
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 10,517
Weighted average remaining lease term:
Operating leases (in years)	3 years 2 months 12 days
Operating Leases, Weighted Average Discount Rate, Percent [Abstract]
Operating leases (percent)	3.40%