Financial Instruments (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	$ 350,000
Derivative, Net Liability Position, Aggregate Fair Value	(42,104)	$ (4,676)
Contract One [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	125,000
Derivative, Net Liability Position, Aggregate Fair Value	(16,630)	(2,914)
Contract Two [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	75,000
Derivative, Net Liability Position, Aggregate Fair Value	(9,993)	(1,762)
Contract Three [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	75,000
Derivative, Net Liability Position, Aggregate Fair Value	(7,914)	0
Contract Four [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	50,000
Derivative, Net Liability Position, Aggregate Fair Value	(5,283)	0
Contract Five [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	25,000
Derivative, Net Liability Position, Aggregate Fair Value	$ (2,284)	$ 0