Consolidating Financial Statements (details) - Consolidating Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Consolidating Statement of Comprehensive Income
Net income	$ 664	$ 812	$ 1,355	$ 1,645
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	879	(1,065)	1,593	(896)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	12	(5)	17	(10)
Net changes in benefit plan assets and obligations	18	23	34	47
Net changes in unrealized foreign currency translation	(35)	94	68	(180)
Other comprehensive income (loss) before income taxes	874	(953)	1,712	(1,039)
Income tax expense (benefit)	323	(353)	590	(328)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	551	(600)	1,122	(711)
Other comprehensive income (loss), net of taxes	551	(600)	1,122	(711)
Comprehensive income	1,215	212	2,477	934
TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	502	628	1,027	1,260
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	570	(719)	1,055	(585)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	6	(5)	8	(9)
Net changes in benefit plan assets and obligations	18	1	18	1
Net changes in unrealized foreign currency translation	25	34	119	(145)
Other comprehensive income (loss) before income taxes	619	(689)	1,200	(738)
Income tax expense (benefit)	216	(246)	397	(232)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	403	(443)	803	(506)
Other comprehensive income (loss), net of taxes	403	(443)	803	(506)
Comprehensive income	905	185	1,830	754
Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	203	245	408	500
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	306	(345)	534	(312)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	6		9	(1)
Net changes in benefit plan assets and obligations	19		20	1
Net changes in unrealized foreign currency translation	(60)	60	(51)	(35)
Other comprehensive income (loss) before income taxes	271	(285)	512	(347)
Income tax expense (benefit)	113	(115)	192	(112)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	158	(170)	320	(235)
Other comprehensive income (loss), net of taxes	158	(170)	320	(235)
Comprehensive income	361	75	728	265
TRV [Member]
Consolidating Statement of Comprehensive Income
Net income	664	812	1,355	1,645
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	3	(1)	4	1
Net changes in benefit plan assets and obligations	(19)	22	(4)	45
Other comprehensive income (loss) before income taxes	(16)	21		46
Income tax expense (benefit)	(6)	8	1	16
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(10)	13	(1)	30
Other comprehensive income (loss) of subsidiaries	561	(613)	1,123	(741)
Other comprehensive income (loss), net of taxes	551	(600)	1,122	(711)
Comprehensive income	1,215	212	2,477	934
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(705)	(873)	(1,435)	(1,760)
Other comprehensive income (loss) of subsidiaries	(561)	613	(1,123)	741
Other comprehensive income (loss), net of taxes	(561)	613	(1,123)	741
Comprehensive income	$ (1,266)	$ (260)	$ (2,558)	$ (1,019)