CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 63,268,660	$ 54,233,151
Fixed maturities, fair value	3,025,790	2,547,210
Equity securities, cost	534,463	589,221
Mortgage loans, securitizations	0	134
Investment real estate, accumulated depreciation	203	251
Other intangibles, accumulated amortization	253,759	197,368
Property and equipment, accumulated depreciation	$ 49,357
Property and equipment, accumulated depreciation		$ 30,989
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	2,000	2,000
Preferred stock, Liquidation preference	$ 2	$ 2
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, shares issued (in shares)	5,000,000	5,000,000
Net unrealized gains (losses) on investments, income tax	$ (383,311)	$ (367,217)
Net unrealized losses relating to other-than-temporary impaired investments for which a portion has been recognized in earnings, income tax	(7,004)	(6,054)
Accumulated gain (loss) - derivatives, income tax	$ (2,123)	$ (2)