Statement of Stockholders Equity Statement - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Divisional Equity [Member]	Retained Earnings [Member]	Accumulated Other Comp (Loss) Income	Treasury Stock [Member]	Noncontrolling Interest [Member]	EID [Member]	EID [Member] Preferred Stock [Member]	EID [Member] Common Stock [Member]	EID [Member] Additional Paid-in Capital [Member]	EID [Member] Divisional Equity [Member]	EID [Member] Retained Earnings [Member]	EID [Member] Accumulated Other Comp (Loss) Income	EID [Member] Treasury Stock [Member]	EID [Member] Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2017	$ 79,593	$ 0	$ 0	$ 80,318	$ 0	$ (1,177)	$ 0	$ 452	$ 79,593	$ 0	$ 0	$ 0	$ 80,557	$ 0	$ (1,177)	$ 0	$ 213
Net (loss) income	(87)			(107)				20	(87)				(105)				18
Other comprehensive (loss) income	1,007					1,007			1,007						1,007
Dividends, Preferred Stock									(2)				(2)
Distributions	(830)			(830)					(831)				(830)				(1)
Issuance of stock	45			45					45				45
Share-based compensation	11			11					11				11
Other	487			434				53	490				434				56
Ending Balance at Mar. 31, 2018	80,226	0	0	79,871	0	(170)	0	525	80,226	0	0	0	80,110	0	(170)	0	286
Beginning Balance at Dec. 31, 2017	79,593	0	0	80,318	0	(1,177)	0	452	79,593	0	0	0	80,557	0	(1,177)	0	213
Net (loss) income	(4,505)								(4,505)
Other comprehensive (loss) income	(1,094)					(1,094)			(1,094)
Distributions	(2,481)								(2,481)
Contributions	288								288
Ending Balance at Sep. 30, 2018	71,999	0	0	73,767	0	(2,271)	0	503	71,999	0	0	0	74,006	0	(2,271)	0	264
Beginning Balance at Mar. 31, 2018	80,226	0	0	79,871	0	(170)	0	525	80,226	0	0	0	80,110	0	(170)	0	286
Net (loss) income	698			694				4	698				697				1
Other comprehensive (loss) income	(2,015)					(2,015)			(2,015)						(2,015)
Dividends, Preferred Stock									(3)				(3)
Distributions	(828)			(828)					(828)				(828)
Issuance of stock	12			12					12				12
Share-based compensation	50			50					50				50
Other	(440)			(409)				(31)	(437)				(409)				(28)
Ending Balance at Jun. 30, 2018	77,703	0	0	79,390	0	(2,185)	0	498	77,703	0	0	0	79,629	0	(2,185)	0	259
Net (loss) income	(5,116)			(5,121)				5	(5,116)				(5,119)				3
Other comprehensive (loss) income	(86)					(86)			(86)						(86)
Dividends, Preferred Stock									(2)				(2)
Distributions	(823)			(823)					(823)				(823)
Issuance of stock	24			24					24				24
Share-based compensation	40			40					40				40
Other	257			257					259				257				2
Ending Balance at Sep. 30, 2018	71,999	0	0	73,767	0	(2,271)	0	503	71,999	0	0	0	74,006	0	(2,271)	0	264
Beginning Balance at Dec. 31, 2018	75,153	0	0	78,020	0	(3,360)	0	493	75,153	0	0	0	78,259	0	(3,360)	0	254
Net (loss) income	176			164				12	176				166				10
Other comprehensive (loss) income	(74)					(74)			(74)						(74)
Dividends, Preferred Stock									(2)				(2)
Distributions	(317)			(317)					(317)				(317)
Contributions	88			88					88				88
Issuance of stock	35			35					35				35
Share-based compensation	18			18					18				18
Other	(5)			(3)				(2)	(3)				(3)
Ending Balance at Mar. 31, 2019	75,074	0	0	78,005	0	(3,434)	0	503	75,074	0	0	0	78,244	0	(3,434)	0	264
Beginning Balance at Dec. 31, 2018	75,153	0	0	78,020	0	(3,360)	0	493	75,153	0	0	0	78,259	0	(3,360)	0	254
Net (loss) income	(923)								(976)
Other comprehensive (loss) income	(521)					(521)			(521)
Distributions	(317)								(317)
Contributions	7,396								3,255
Ending Balance at Sep. 30, 2019	25,261	7	28,072	0	(397)	(2,667)	0	246	21,191	239	0	23,963	0	(351)	(2,667)	0	7
Beginning Balance at Mar. 31, 2019	75,074	0	0	78,005	0	(3,434)	0	503	75,074	0	0	0	78,244	0	(3,434)	0	264
Net (loss) income	(594)			(805)	197			14	(617)				(806)	180			9
Other comprehensive (loss) income	(155)					(155)			(155)						(155)
Dividends, Common Stock	(97)				(97)
Dividends, Preferred Stock									(5)					(5)
Contributions	7,308			7,308					3,168				3,168
Issuance of stock	4			4					4				4
Share-based compensation	55		11	44					55			11	44
Impact of Internal Reorganization	(55,496)			(56,479)		1,214		(231)	(55,496)				(56,479)		1,214		(231)
Reclassification of Divisional Equity to APIC	0	7	28,070	(28,077)					0	239		23,936	(24,175)
Other	(32)				(3)			(29)	(27)					(3)			(24)
Ending Balance at Jun. 30, 2019	26,067	7	28,081	0	97	(2,375)	0	257	22,001	239	0	23,947	0	172	(2,375)	0	18
Net (loss) income	(505)				(494)			(11)	(535)					(524)			(11)
Other comprehensive (loss) income	(292)					(292)			(292)						(292)
Dividends, Preferred Stock									4			4
Issuance of stock	4		4
Share-based compensation	12		12						12			12
Common stock repurchase	(25)		(25)
Other									1					1
Ending Balance at Sep. 30, 2019	$ 25,261	$ 7	$ 28,072	$ 0	$ (397)	$ (2,667)	$ 0	$ 246	$ 21,191	$ 239	$ 0	$ 23,963	$ 0	$ (351)	$ (2,667)	$ 0	$ 7