Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			$ 281,442
Income tax benefit (expense)	$ (68,391)	$ (38,512)	(40,104)	$ (72,145)
Ending Balance	428,477		428,477
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			(7,917)	(17,448)
Change in OCI before reclassifications			(3,888)	7,007
Amounts reclassified from AOCI			0	0
Income tax benefit (expense)			12	2
Ending Balance	(11,793)	(10,439)	(11,793)	(10,439)
Net unrealized investment gains (losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			289,359	(10,848)
Change in OCI before reclassifications			195,529	332,927
Amounts reclassified from AOCI			(4,502)	10,672
Income tax benefit (expense)			(40,116)	(72,147)
Ending Balance	440,270	260,604	440,270	260,604
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			281,442	(28,296)
Change in OCI before reclassifications			191,641	339,934
Amounts reclassified from AOCI			(4,502)	10,672
Income tax benefit (expense)			(40,104)	(72,145)
Ending Balance	428,477	250,165	428,477	250,165
Cash flow hedges | Net unrealized investment gains (losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance			26,000	(18,000)
Ending Balance	$ 94,000	$ 29,000	$ 94,000	$ 29,000