Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 160,422	$ 495,607	$ 182,667
Other comprehensive income (loss), net of tax
Change in net unrealized gains (losses) on securities	(136,261)	169,740	93,704
Foreign currency transaction and translation adjustments	(900)	746	289
Defined benefit pension plan adjustment	22,326	15,831	9,286
Other comprehensive income (loss), net of tax	(114,835)	186,317	103,279
Total comprehensive income	45,587	681,924	285,946
Less: Comprehensive income attributable to noncontrolling interest	1,427	1,956	1,664
Total comprehensive income attributable to American National	$ 44,160	$ 679,968	$ 284,282