Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock	Noncontrolling Interest
Balance at beginning of the period at Dec. 31, 2016	$ 4,661,495	$ 30,832	$ 16,406	$ 455,899	$ 4,250,818	$ (101,777)	$ 9,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury shares	2,125		1,964			161
Amortization of restricted stock	823		823
Other comprehensive income (loss)	186,317			186,317
Net income attributable to American National	493,651				493,651
Cash dividends to common stockholders	(88,335)				(88,335)
Contributions	26						26
Distributions	(2,287)						(2,287)
Net income attributable to noncontrolling interest	1,956						1,956
Balance at end of the period at Dec. 31, 2017	5,255,771	30,832	19,193	642,216	4,656,134	(101,616)	9,012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury shares	(5,703)		1,173			(6,876)
Amortization of restricted stock	328		328
Cumulative effect of accounting change	59,932			(627,119)	687,051
Other comprehensive income (loss)	(114,835)			(114,835)
Net income attributable to American National	158,995				158,995
Cash dividends to common stockholders	(88,228)				(88,228)
Contributions	6,182						6,182
Distributions	(2,354)						(2,354)
Net income attributable to noncontrolling interest	1,427						1,427
Balance at end of the period at Dec. 31, 2018	5,271,515	30,832	20,694	(99,738)	5,413,952	(108,492)	14,267
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reissuance of treasury shares	260		237			23
Amortization of restricted stock	80		80
Cumulative effect of accounting change	0			(785)	785
Other comprehensive income (loss)	200,041			200,041
Net income attributable to American National	620,363				620,363
Cash dividends to common stockholders	(88,243)				(88,243)
Contributions	388						388
Distributions	(20,055)						(20,055)
Net income attributable to noncontrolling interest	11,414						11,414
Balance at end of the period at Dec. 31, 2019	$ 5,995,763	$ 30,832	$ 21,011	$ 99,518	$ 5,946,857	$ (108,469)	$ 6,014