Allowance for Credit Losses (Narrative) (Details) - USD ($)		12 Months Ended
	Jan. 01, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Time period used for projecting future conditions to estimate credit losses		2 years
Provision for credit losses		$ (81,500,000)	$ 125,000,000	$ (14,500,000)
Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery		(6,300,000)	3,200,000	(700,000)
Other-than-temporary impairment loss, debt securities, portion recognized in earnings	$ 4,400,000	0	0	300,000
Other financial assets, allowance for credit loss, excluding accrued interest		1,000,000	800,000	$ 0
Other Financial Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, accrued interest, writeoff		$ 0	$ 0