Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2020		Dec. 31, 2019
Fixed maturity securities, available for sale, amortized cost	$ 46,951,043	[1]	$ 48,238,946
Fixed maturity securities, available for sale, allowance for credit losses	50,186
Mortgage loans on real estate, allowance for credit losses	20,089		9,179
Coinsurance deposits, allowance for credit losses	$ 3,948		$ 0
Stockholders' equity:
Common stock, par value (dollars per share)	$ 1		$ 1
Common stock, shares authorized	200,000,000		200,000,000
Common stock, shares issued	91,595,066		91,107,555
Common stock, shares outstanding	91,595,066		91,107,555
Common stock, shares held in treasury	1,171,451		1,344,193
Preferred Stock, Series A
Stockholders' equity:
Preferred stock, par value (dollars per share)	$ 1		$ 1
Preferred stock, aggregate liquidation preference	$ 400,000		$ 400,000
Preferred stock, shares authorized	20,000		20,000
Preferred stock, shares issued	16,000		16,000
Preferred stock, shares outstanding	16,000		16,000
Preferred Stock, Series B
Stockholders' equity:
Preferred stock, par value (dollars per share)	$ 1
Preferred stock, aggregate liquidation preference	$ 300,000
Preferred stock, shares authorized	12,000
Preferred stock, shares issued	12,000
Preferred stock, shares outstanding	12,000

[1] (1) Amortized cost excludes accrued interest receivable of $432.0 million as of June 30, 2020.