Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (220,597)	$ 256,867
Other comprehensive income (loss), net of tax
Change in net unrealized gains (losses) on securities	(112,403)	85,514
Foreign currency transaction and translation adjustments	(924)	(156)
Defined benefit pension plan adjustment	1,756	1,416
Total other comprehensive income (loss), net of tax	(111,571)	86,774
Total comprehensive income (loss)	(332,168)	343,641
Less: Comprehensive loss attributable to noncontrolling interest	(153)	(1,350)
Total comprehensive income (loss) attributable to American National	$ (332,015)	$ 344,991