Investments - Components of Net Realized and Unrealized Gain (Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net realized gains (losses)	$ 151,480	$ 122,024	$ 80,437
Net unrealized gains (losses)	(130)	(59,614)	3,431
Net realized and unrealized gains (losses)	151,350	62,410	83,868
Operating segments
Segment Reporting Information [Line Items]
Net gains from recoveries (credit losses) on AFS securities			0
Insurance
Segment Reporting Information [Line Items]
Net gains from recoveries (credit losses) on AFS securities		53
Insurance | Operating segments
Segment Reporting Information [Line Items]
Net gains from recoveries (credit losses) on AFS securities	(245)	53
AFS securities | Insurance | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	638	528	1,312
Corporate loans | Insurance | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	(389)	(945)	2,100
Net unrealized gains (losses)	1,330	(1,461)	(3,899)
Corporate loans | Mortgage | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	91,538	111,725	52,617
Net unrealized gains (losses)	(1,127)	1,270	840
Dividends from equity securities | Other
Segment Reporting Information [Line Items]
Net unrealized gains (losses)	3,090	(67,656)	(992)
Dividends from equity securities | Insurance | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	(10,434)	(24,586)	947
Net unrealized gains (losses)	12,445	(22,793)	7,621
Dividends from equity securities | Dividends from equity securities | Insurance | Operating segments
Segment Reporting Information [Line Items]
Net unrealized gains (losses)	(814)	17,290	(807)
Other Corporate Bonds | Insurance | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	3,917	7,299	279
Other investments | Other
Segment Reporting Information [Line Items]
Net realized gains (losses)	1,632	(4,713)	(260)
Net unrealized gains (losses)	(5,801)	7,482	25
Other investments | Insurance | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	1,346	2,511	39
Net unrealized gains (losses)	(9,800)	10,162	(697)
Other investments | Mortgage | Operating segments
Segment Reporting Information [Line Items]
Net realized gains (losses)	2,165	(10,314)	0
Net unrealized gains (losses)	(268)	(6,093)	357
Mortgage loans held for sale | Other
Segment Reporting Information [Line Items]
Net realized gains (losses)	61,312	40,466	23,403
Net unrealized gains (losses)	$ 815	$ 2,185	$ 983