Accumulated Other Comprehensive Income (Amounts Reclassified from AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income [Line Items]
Acceleration of 2020 Swap	$ 7,485	$ 6,945	$ 24,970	$ 20,529
Nonoperating Income (Expense)	(7,155)	39,218	(10,747)	13,383
Interest Rate Swap | Reclassification out of Accumulated Other Comprehensive Income | Derivative Instruments
Accumulated Other Comprehensive Income [Line Items]
Interest Expense - Amortization of Derivative Instruments	103	83	308	131
Interest Expense - Settlement Payments	2,250	(287)	4,338	(1,413)
Acceleration of 2020 Swap	201	0	201	0
Nonoperating Income (Expense)	$ 2,554	$ (204)	$ 4,847	$ (1,282)