Leasing Arrangements - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 2,363
Operating cash flows from finance leases	8
Financing cash flows from finance leases	338	$ 6
Right-of-use assets, net obtained in exchange for new lease obligations:
Operating leases	23,695
Finance leases	$ 71