Other Expenses (Other Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other Income and Expenses [Abstract]
Employee related costs	$ 921	$ 935	$ 2,752	$ 2,751
Third party staffing costs	435	413	1,217	1,173
General and administrative expenses	290	229	884	768
Pension, postretirement and postemployment benefit costs	45	86	141	241
Premium taxes, other taxes, and licenses & fees	193	145	559	468
Commissions and other variable expenses	1,403	1,393	4,257	4,003
Capitalization of DAC	(810)	(761)	(2,440)	(2,218)
Amortization of DAC and VOBA	732	626	2,132	1,945
Amortization of negative VOBA	(7)	(32)	(45)	(113)
Interest expense on debt	267	284	862	851
Total other expenses	$ 3,469	$ 3,318	$ 10,319	$ 9,869