Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Other	$ 420	$ 614
Long-term debt	46,061	60,579
Less current maturities	23,155	24,372
Total	22,906	36,207
4.1% Loans Payable [Member]
Debt Instrument [Line Items]
Long-term debt	11,291
1.2% Loans Payable [Member]
Debt Instrument [Line Items]
Long-term debt	$ 34,350	$ 59,965