Financial Instruments - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Long Term Debt Percentage Bearing Fixed Interest Percentage	78.00%
Gain/Loss on FX Effectiveness		$ 0
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 700
Designated as Hedging Instrument [Member] | June 2019 4 YR Cross Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Amount of Hedged Item	$ 50,000
Derivative, Fixed Interest Rate	0.82%
Designated as Hedging Instrument [Member] | June 2019 2 YR Cross Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Amount of Hedged Item	$ 50,000
Derivative, Fixed Interest Rate	0.95%
Designated as Hedging Instrument [Member] | February 2019 Cross Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Amount of Hedged Item	$ 50,000
Derivative, Fixed Interest Rate	0.78%
Designated as Hedging Instrument [Member] | 2.25% $100 Million Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Amount of Hedged Item	$ 100,000
Derivative, Fixed Interest Rate	2.25%
Designated as Hedging Instrument [Member] | 2.52% $50 Million Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Amount of Hedged Item	$ 50,000
Derivative, Fixed Interest Rate	2.52%
Gain/Loss on IR Effectiveness	$ 0	0
Designated as Hedging Instrument [Member] | Cross Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain/Loss on FX Effectiveness	0
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Amount of Hedged Item	536,500	494,600
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ (4,800)	$ 3,700	$ 1,200