Schedule II - Condensed Financial Information, Statements of Cash Flows (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities
Shareholders' net income	$ 1,476	$ 1,623	$ 1,260
Adjustments to reconcile net income to net cash provided by operating activities:
Other liabilities	(483)	(132)	344
Other, net	(67)	28	(30)
Net cash provided by operating activities	719	2,350	1,491
Cash Flows from Investing Activities
Net cash provided by/ (used in) investing activities	15	(3,857)	(1,270)
Cash Flows from Financing Activities
Net change in short-term debt	(101)	98	0
Net proceeds on issuance of long-term debt	0	0	2,676
Repayment of long-term debt	(15)	(326)	(451)
Issuance of common stock	150	121	734
Common dividends paid	(11)	(11)	(11)
Repurchase of common stock	(1,003)	(208)	(225)
Net cash (used in) / provided by financing activities	(930)	(228)	2,867
Net increase (decrease) in cash and cash equivalents	(183)	(1,712)	3,085
Cash and cash equivalents, beginning of year	2,978	4,690	1,605
Cash and cash equivalents, end of year	2,795	2,978	4,690
Parent Company [Member]
Cash Flows from Operating Activities
Shareholders' net income	1,476	1,623	1,260
Adjustments to reconcile net income to net cash provided by operating activities:
Equity In Income Of Subsidiaries	(1,702)	(1,932)	(1,459)
Dividends received from subsidiaries	506	671	1,135
Other liabilities	(245)	(213)	(296)
Other, net	63	191	(92)
Net cash provided by operating activities	98	340	548
Cash Flows from Investing Activities
Other, net	0	(19)	0
Net cash provided by/ (used in) investing activities	0	(19)	0
Cash Flows from Financing Activities
Net change in amounts due to / from affiliates	751	(208)	(3,258)
Net change in short-term debt	(100)	100	0
Net proceeds on issuance of long-term debt	0	0	2,661
Repayment of long-term debt	0	0	(449)
Issuance of common stock	150	121	734
Common dividends paid	(11)	(11)	(11)
Repurchase of common stock	(1,003)	(208)	(225)
Net cash (used in) / provided by financing activities	(213)	(206)	(548)
Net increase (decrease) in cash and cash equivalents	(115)	115	0
Cash and cash equivalents, beginning of year	115	0	0
Cash and cash equivalents, end of year	$ 0	$ 115	$ 0