Leases - Lease Cost (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 12,492
Amortization of right-of-use assets	256
Interest on lease liabilities	113
Total finance lease cost	369
Short-term lease cost	1,915
Total Lease Cost	14,776
Operating cash flows for operating leases	12,616
Operating cash flows for finance leases	113
Financing activities for finance leases	394
Right-of-use assets obtained in exchange for new operating lease liabilties	$ 3,164
Operating leases	7 years 3 months 12 days
Finance leases	3 years 4 months 12 days
Operating leases	4.71%
Finance leases	8.27%