Condensed Financial Information (Parent Company) (Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended								5 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net income (loss)	$ 1,442,000	$ (271,000)	$ (239,000)	$ (67,000)	$ 668,000	$ (943,000)	$ 246,000	$ (349,000)		$ 865,000	$ (378,000)	$ (2,939,000)
Other, net										110,000	129,000	132,000
Net cash provided by (used in) operating activities										3,062,000	3,396,000	3,736,000
Cash flows from investing activities
Sales of fixed maturity securities										15,819,000	17,214,000	46,130,000
Purchases of fixed maturity securities										(16,460,000)	(18,782,000)	(39,687,000)
Net cash provided by (used in) investing activities										(4,538,000)	(3,915,000)	4,674,000
Cash flows from financing activities
Treasury stock acquired in connection with share repurchases										(105,000)	0	0
Distribution to MetLife, Inc.										0	(1,798,000)	0
Net cash provided by (used in) financing activities										3,764,000	(2,852,000)	(4,752,000)
Change in cash, cash equivalents and restricted cash										2,288,000	(3,371,000)	3,658,000
Cash, cash equivalents and restricted cash, beginning of year				1,857,000				5,228,000		1,857,000	5,228,000	1,570,000
Cash, cash equivalents and restricted cash, end of year	4,145,000				1,857,000				$ 5,228,000	4,145,000	1,857,000	5,228,000
Supplemental disclosures of cash flow information
Net cash paid (received) for interest										159,000	155,000	186,000
Net cash paid (received) for income tax										(895,000)	(637,000)	189,000
Parent Company
Cash flows from operating activities
Net income (loss)									(569)	864,550	(378,118)
Equity in (earnings) losses of subsidiaries									0	(1,003,123)	565,979
Distribution from subsidiary									0	51,900	50,000
Other, net									569	8,144	(252,310)
Net cash provided by (used in) operating activities									0	(78,529)	(14,449)
Cash flows from investing activities
Sales of fixed maturity securities									0	3,484	509,814
Purchases of fixed maturity securities									0	0	(748,972)
Capital contributions to subsidiary									0	(208,000)	(1,300,000)
Net cash provided by (used in) investing activities									0	(204,516)	(1,539,158)
Cash flows from financing activities
Long-term and short-term debt issued									0	892,500	3,724,375
Long-term and short-term debt repaid									0	(350,964)	0
Debt issuance costs									0	(12,143)	(39,187)
Issuance of common stock									1	0	0
Treasury stock acquired in connection with share repurchases									0	(105,253)	0
Distribution to MetLife, Inc.									0	0	(1,798,000)
Credit facility fees									0	(5,738)	(8,054)
Net cash provided by (used in) financing activities									1	418,402	1,879,134
Change in cash, cash equivalents and restricted cash									1	135,357	325,527
Cash, cash equivalents and restricted cash, beginning of year				$ 325,528				$ 1		325,528	1
Cash, cash equivalents and restricted cash, end of year	$ 460,885				$ 325,528				1	460,885	325,528	$ 1
Supplemental disclosures of cash flow information
Net cash paid (received) for interest									0	158,022	67,135
Cash received from MetLife, Inc. for income tax									0	(6,902)	(40)
Income tax paid by Brighthouse Financial, Inc.									0	746	888
Net cash paid (received) for income tax									$ 0	$ (6,156)	$ 848