Debt Interest Rate Swaps 2 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative
Gain on cash flow hedge ineffectiveness		$ 1,200	$ 2,400
Loss on Cash Flow Hedge Ineffectiveness	$ (500)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		$ 1,400	$ 1,900
Interest Rate Swap 4
Derivative
Interest rate swap agreement, fixed interest rate	1.1425%
Derivative, Notional Amount	$ 150,000