Leases Leases - Supplemental Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating Lease, Payments	$ 6,563
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	5,980
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 535
Operating Lease, Weighted Average Remaining Lease Term	4 years 9 months 21 days
Finance Lease, Weighted Average Remaining Lease Term	7 years
Operating Lease, Weighted Average Discount Rate, Percent	3.70%
Finance Lease, Weighted Average Discount Rate, Percent	3.40%