Leases - Other Lease Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating cash outflows for amounts included in the measurement of lease liabilities	$ 4,510	$ 9,871
Right-of-use assets obtained in exchange for lease obligations	$ 3,964	$ 4,262
Weighted average remaining lease term	4 years 5 months 8 days	4 years 5 months 8 days
Weighted average discount rate	3.20%	3.20%