Lease Commitments - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 8,265	$ 25,446
Operating cash flows from finance leases	51	160
Financing cash flows from finance leases	(185)	(574)
Leased assets obtained in exchange for new finance lease liabilities	$ 0	$ 39