Consolidating Financial Statements (details) - Consolidating Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Consolidating Statement of Comprehensive Income
Net income	$ 716	$ 928	$ 2,071	$ 2,573
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(455)	67	1,138	(829)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	6	(3)	23	(13)
Net changes in benefit plan assets and obligations	16	24	50	71
Net changes in unrealized foreign currency translation	(31)	(227)	37	(407)
Other comprehensive income (loss) before income taxes	(464)	(139)	1,248	(1,178)
Income tax expense (benefit)	(159)	(2)	431	(330)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(305)	(137)	817	(848)
Other comprehensive income (loss), net of taxes	(305)	(137)	817	(848)
Comprehensive income	411	791	2,888	1,725
TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	538	699	1,565	1,959
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(323)	93	732	(492)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	4	(2)	12	(11)
Net changes in benefit plan assets and obligations	1	1	19	2
Net changes in unrealized foreign currency translation	(13)	(148)	106	(293)
Other comprehensive income (loss) before income taxes	(331)	(56)	869	(794)
Income tax expense (benefit)	(120)	8	277	(224)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(211)	(64)	592	(570)
Other comprehensive income (loss), net of taxes	(211)	(64)	592	(570)
Comprehensive income	327	635	2,157	1,389
Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	213	287	621	787
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(137)	(17)	397	(329)
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	2	(1)	11	(2)
Net changes in benefit plan assets and obligations		1	20	2
Net changes in unrealized foreign currency translation	(18)	(79)	(69)	(114)
Other comprehensive income (loss) before income taxes	(153)	(96)	359	(443)
Income tax expense (benefit)	(48)	(14)	144	(126)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(105)	(82)	215	(317)
Other comprehensive income (loss), net of taxes	(105)	(82)	215	(317)
Comprehensive income	108	205	836	470
TRV [Member]
Consolidating Statement of Comprehensive Income
Net income	716	928	2,071	2,573
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	5	(9)	9	(8)
Net changes in benefit plan assets and obligations	15	22	11	67
Other comprehensive income (loss) before income taxes	20	13	20	59
Income tax expense (benefit)	9	4	10	20
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	11	9	10	39
Other comprehensive income (loss) of subsidiaries	(316)	(146)	807	(887)
Other comprehensive income (loss), net of taxes	(305)	(137)	817	(848)
Comprehensive income	411	791	2,888	1,725
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(751)	(986)	(2,186)	(2,746)
Other comprehensive income (loss) of subsidiaries	316	146	(807)	887
Other comprehensive income (loss), net of taxes	316	146	(807)	887
Comprehensive income	$ (435)	$ (840)	$ (2,993)	$ (1,859)