Leasing Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Capital Leases
2019	$ 437
2020	21
2021	0
2022	0
2023	0
Subsequent to 2023	0
Total minimum lease payments	458
Amounts representing interest	8
Present value of net minimum lease payments	450
Current maturities	429
Long-term capital lease obligation	21
Operating Leases
2019	2,387
2020	2,174
2021	2,092
2022	2,116
2023	1,659
Subsequent to 2023	10,959
Total minimum lease payments	21,387
Rental expense for all operating leases	3,700	$ 4,900
Rental income on subleases of equipment	900	600
Assets recorded under capital leases
Plant and equipment	3,085	4,807
Less accumulated depreciation	2,681	3,730
Assets recorded under capital leases	$ 404	$ 1,077