Other Expenses (Other Expenses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Income and Expenses [Abstract]
Employee related costs	$ 937	$ 937
Third party staffing costs	380	362
General and administrative expenses	243	221
Pension, postretirement and postemployment benefit costs	49	79
Premium taxes, other taxes, and licenses & fees	179	175
Commissions and other variable expenses	1,416	1,304
Capitalization of DAC	(796)	(713)
Amortization of DAC and VOBA	693	663
Amortization of negative VOBA	(22)	(43)
Interest expense on debt	286	283
Total other expenses	$ 3,365	$ 3,268