Condensed Financial Information (Parent Company) (Condensed Balance Sheets Phantom) (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements, Captions [Line Items]
Amortized cost of fixed maturity securities available-for-sale	$ 64,079,000	$ 60,920,000
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred Stock, Liquidation Preference, Value	$ 425,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	120,647,871	120,448,018
Common stock, shares outstanding	106,027,301	117,532,336	119,773,106	100,000
Treasury Stock, Shares	14,620,570	2,915,682
Parent Company
Condensed Balance Sheet Statements, Captions [Line Items]
Amortized cost of fixed maturity securities available-for-sale	$ 44,000	$ 235,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	120,647,871	120,448,018
Common stock, shares outstanding	106,027,301	117,532,336