Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows from Operating Activities
Net Income		$ 1,843	$ 2,077	$ 2,094
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization		610	585	588
Realized investment (gains) losses		(169)	(57)	(154)
Deferred income taxes		74	21	(22)
Net changes in assets and liabilities, net of non-operating effects:
Premiums, accounts and notes receivable		663	(945)	(780)
Reinsurance recoverables		142	55	22
Deferred policy acquisition costs		(213)	(182)	(176)
Other assets		134	16	(265)
Insurance liabilities		683	657	457
Accounts payable, accrued expenses and other liabilities		124	423	202
Current income taxes		1	(25)	111
Loss on extinguishment of debt		0	100	0
Distributions from partnership investments	[1]	144	137	111
Other, net	[2]	(10)	71	(30)
Net cash provided by (used in) operating activities	[1],[2]	4,026	2,933	2,158
Proceeds from investments sold:
Fixed maturities and equity securities		1,544	1,555	1,769
Investment maturities and repayments:
Fixed maturities and equity securities		1,755	1,435	1,640
Commercial mortgage loans		316	640	453
Other sales, maturities and repayments (primarily short-term and other long-term investments)	[1]	1,431	1,160	2,595
Investments purchased or originated:
Fixed maturities and equity securities		(5,191)	(4,234)	(5,424)
Commercial mortgage loans		(165)	(500)	(287)
Other (primarily short-term and other long-term investments)		(1,698)	(1,183)	(2,115)
Property and equipment purchases, net		(461)	(510)	(473)
Acquisitions, net of cash acquired		(4)	(99)	0
Other, net		(101)	0	(24)
Net cash provided by (used in) investing activities	[1]	(2,574)	(1,736)	(1,866)
Cash Flows from Financing Activities
Deposits and interest credited to contractholder deposit funds		1,460	1,429	1,482
Withdrawals and benefit payments from contractholder deposit funds		(1,362)	(1,359)	(1,456)
Net change in short-term debt		(148)	(21)	(112)
Net proceeds on issuance of long-term debt		0	894	0
Repayment of long-term debt		0	(938)	0
Repurchase of common stock		(139)	(671)	(1,612)
Issuance of common stock		36	154	110
Other, net	[2]	(72)	(97)	(47)
Net cash provided by (used in) financing activities	[2]	(225)	(609)	(1,635)
Effect of foreign currency rate changes on cash and cash equivalents		(10)	(40)	(32)
Net increase / (decrease) in cash and cash equivalents		1,217	548	(1,375)
Cash and cash equivalents, January 1		1,968	1,420	2,795
Cash and cash equivalents, December 31		3,185	1,968	1,420
Supplemental Disclosure of Cash Information:
Income taxes paid, net of refunds		1,064	1,194	1,085
Interest paid		$ 244	$ 245	$ 259

[1] As required in adopting ASU 2016-15, the Company retrospectively reclassified $137 million in 2015 and $111 million in 2014 of cash distributions of earnings from partnership investments from investing to operating activities. The comparable amount reported in operating activities in 2016 was $144 million. See Note 2 for further discussion.

[2] As required in adopting Accounting Standard Update ("ASU") 2016-09, the Company retrospectively reclassified $79 million in 2015 and $53 million in 2014 of cash payments from operating to financing activities. These payments were related to employee tax obligations associated with stock compensation. The comparable amount reported in financing activities in 2016 was $72 million. See Note 2 for further discussion.