Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended									12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Impact of revisions on previously issued consolidated statements of operations
Other income (expense), net	$ (59)	$ (68)	$ (52)	$ (56)	$ (47)	$ (53)	$ (50)	$ (68)	$ (58)	$ (223)	$ (229)	$ (168)
Income (loss) from continuing operations before income taxes	93	73	160	132	85	(22)	58	(14)	51	450	73	(383)
Income (loss) from continuing operations	88	53	122	93	71	(59)	42	(45)	44	339	(18)	(343)
Net income (loss)	86	59	120	88	62	(76)	31	(69)	35	329	(79)	(524)
Impact of previously issued consolidated statement of cash flows
Other assets	177	185	187	188	196	192				185	192
Total assets	6,880	6,957	7,080	7,077	6,793	6,883				6,957	6,883
Cash and cash investments	906	1,223		1,028	828	1,040				1,223	1,040
Short-term bank deposits				195	204
Net cash (for) from investing activities	(6)			62	70
Accounting for certain investments in private equity limited partnership funds | As Reported
Impact of revisions on previously issued consolidated statements of operations
Other income (expense), net		(71)	(58)	(57)	(53)	(57)	(57)	(66)	(49)	(239)	(229)	(177)
Income (loss) from continuing operations before income taxes		70	154	131	79	(26)	51	(12)	60	434	73	(392)
Income (loss) from continuing operations		50	116	92	65	(63)	35	(43)	(53)	323	(18)	(352)
Net income (loss)		56	114	87	56	(80)	24	(67)	44	313	(79)	(533)
Impact of previously issued consolidated statement of cash flows
Other assets		161	166	173	182	184				161	184
Total assets		6,933	7,059	7,062	6,779	6,875				6,933	6,875
Accounting for certain investments in private equity limited partnership funds | Correction
Impact of revisions on previously issued consolidated statements of operations
Other income (expense), net		3	6	1	6	4	7	(2)	(9)	16		9
Income (loss) from continuing operations before income taxes		3	6	1	6	4	7	(2)	(9)	16		9
Income (loss) from continuing operations		3	6	1	6	4	7	(2)	(9)	16		9
Net income (loss)		3	6	1	6	4	7	(2)	(9)	16		9
Impact of previously issued consolidated statement of cash flows
Other assets		24	21	15	14	8				24	8
Total assets		24	21	15	14	8				24	8
Classification of cash and cash investments | As Reported
Impact of previously issued consolidated statement of cash flows
Cash and cash investments				1,223	1,032
Net cash (for) from investing activities				$ (51)	$ (30)
Foreign short-term bank deposits | Minimum
Impact of previously issued consolidated statement of cash flows
Term	3 months
Foreign short-term bank deposits | Maximum
Impact of previously issued consolidated statement of cash flows
Term	12 months