Fair-Value Measurements (Narrative) (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized (losses) gains from valuation of embedded derivatives		$ 10,284	$ (32,377)
Carrying value of senior unsecured notes	$ 2,888,422	2,888,422		$ 2,930,505
Embedded Derivative Financial Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized (losses) gains from valuation of embedded derivatives	(10,700)	(6,400)	$ (32,800)
Carrying value of senior unsecured notes	2,900,000	2,900,000		3,000,000
Fair value of senior unsecured notes	$ 2,600,000	$ 2,600,000		$ 3,000,000
Equity Volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Embedded derivative liability, measurement input	0.50	0.50