Schedule I - Condensed Financial Information Of Registrant (Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	$ 4,840	$ 3,768
Total financial assets measured at fair value	4,840	3,768
Face Value	2,743,800	2,758,800
Fair Value	3,229,118	3,370,588
Debt Issuance Costs, Net	25,200	26,000
Debt Instrument, Unamortized Discount	6,400	6,600
Fixed Rate [Member]
Face Value	2,683,800	2,683,800
Fair Value	3,169,118	3,295,588
Variable Rate [Member]
Face Value	60,000	75,000
Fair Value	60,000	75,000
Parent Company [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	3,605	3,225
Investments, Fair Value Disclosure	3,605	3,225
Total financial assets measured at fair value	3,605	3,225
Other derivative liabilities	49,382	63,215
Total financial liabilities measured at fair value	49,382	63,215
Face Value	880,000	880,000
Fair Value	946,346	992,615
Debt Issuance Costs, Net	7,319	8,600
Debt Instrument, Unamortized Discount	527	625
Parent Company [Member] | Fixed Rate [Member]
Face Value	880,000	880,000
Fair Value	946,346	992,615
Parent Company [Member] | Variable Rate [Member]
Face Value	0	0
Fair Value	0	0
Fair Value, Inputs, Level 1 [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	11	16
Total financial assets measured at fair value	11	16
Fair Value, Inputs, Level 1 [Member] | Parent Company [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	11	16
Investments, Fair Value Disclosure	11	16
Total financial assets measured at fair value	11	16
Other derivative liabilities	0	0
Total financial liabilities measured at fair value	0	0
Significant Observable Inputs (Level 2) [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	3,594	3,209
Total financial assets measured at fair value	3,594	3,209
Significant Observable Inputs (Level 2) [Member] | Parent Company [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	3,594	3,209
Investments, Fair Value Disclosure	3,594	3,209
Total financial assets measured at fair value	3,594	3,209
Other derivative liabilities	49,382	63,215
Total financial liabilities measured at fair value	49,382	63,215
Unobservable Inputs (Level 3) [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	1,235	543
Total financial assets measured at fair value	1,235	543
Unobservable Inputs (Level 3) [Member] | Parent Company [Member]
Condensed Financial Information Disclosure [Abstract]
Total financial assets measured at fair value	0	0
Investments, Fair Value Disclosure	0	0
Total financial assets measured at fair value	0	0
Other derivative liabilities	0	0
Total financial liabilities measured at fair value	0	0
Money Market Funds [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	11	16
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	11	16
Money Market Funds [Member] | Significant Observable Inputs (Level 2) [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	0	0
Money Market Funds [Member] | Unobservable Inputs (Level 3) [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	0	0
Mutual Fund [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	3,594	3,209
Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	0	0
Mutual Fund [Member] | Significant Observable Inputs (Level 2) [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	3,594	3,209
Mutual Fund [Member] | Unobservable Inputs (Level 3) [Member] | Parent Company [Member]
Investments, Fair Value Disclosure	$ 0	$ 0