Consolidating Financial Information (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income	$ 283	$ 267	$ 790	$ 806
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization			30	28
Pension and other postretirement benefits contributions			(41)	(33)
Pension and other postretirement benefits expense			34	22
Deferred income taxes			(1)	(7)
Share-based compensation			14	11
Excess tax benefits from share-based payment arrangements			(9)	(3)
Changes in operating assets and liabilities:
Accounts and other receivables			(13)	(9)
Inventories			(124)	(42)
Accounts payable and accrued liabilities			54	(17)
Settlement costs			(84)	(3)
Income taxes			(17)	(55)
Other current assets			6	(6)
Other assets			2
Net cash provided by (used in) operating activities			641	692
Cash flows from investing activities:
Business acquisition, net of cash acquired			(135)
Additions to plant and equipment			(51)	(33)
Net cash (used in) investing activities			(186)	(33)
Cash flows from financing activities:
Shares repurchased			(274)	(1,221)
Dividends paid			(608)	(550)
Proceeds from issuance of long-term debt			500	750
Debt issuance costs			(6)	(6)
Proceeds from exercise of stock options			5	7
Excess tax benefits from share-based payment arrangements			9	3
Net cash (used in) provided by financing activities			(374)	(1,017)
Change in cash and cash equivalents			81	(358)
Cash and cash equivalents, beginning of year			1,634	2,063
Cash and cash equivalents, end of period	1,715	1,705	1,715	1,705
Parent [Member]
Cash flows from operating activities:
Net income	283	267	790	806
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity income from subsidiaries	(283)	(267)	(791)	(806)
Deferred income taxes			(1)
Share-based compensation			1
Changes in operating assets and liabilities:
Accounts and other receivables				1
Accounts payable and accrued liabilities			(4)	17
Other assets			(125)
Return on investment in subsidiaries			1,021	2,196
Net cash provided by (used in) operating activities			891	2,214
Cash flows from investing activities:
Investment in subsidiary			(50)
Net cash (used in) investing activities			(50)
Cash flows from financing activities:
Shares repurchased			(274)	(1,221)
Dividends paid			(608)	(550)
Net cash (used in) provided by financing activities			(882)	(1,771)
Change in cash and cash equivalents			(41)	443
Cash and cash equivalents, beginning of year			235	163
Cash and cash equivalents, end of period	194	606	194	606
Issuer [Member]
Cash flows from operating activities:
Net income	287	267	796	806
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity income from subsidiaries	(171)	(168)	(505)	(497)
Depreciation and amortization			30	28
Pension and other postretirement benefits contributions			(41)	(33)
Pension and other postretirement benefits expense			34	22
Deferred income taxes			1	(8)
Share-based compensation			13	11
Excess tax benefits from share-based payment arrangements			(9)	(3)
Changes in operating assets and liabilities:
Accounts and other receivables			864	(10)
Inventories			(110)	(42)
Accounts payable and accrued liabilities			60	(14)
Settlement costs			(84)	(3)
Income taxes			(15)	(55)
Other current assets			17	(6)
Other assets			2
Return on investment in subsidiaries				550
Net cash provided by (used in) operating activities			1,053	746
Cash flows from investing activities:
Additions to plant and equipment			(51)	(33)
Net cash (used in) investing activities			(51)
Cash flows from financing activities:
Dividends paid			(1,021)	(2,196)
Proceeds from issuance of long-term debt			500	750
Debt issuance costs			(6)	(6)
Proceeds from exercise of stock options			5	7
Excess tax benefits from share-based payment arrangements			9	3
Net cash (used in) provided by financing activities			(513)	(1,442)
Change in cash and cash equivalents			489	(729)
Cash and cash equivalents, beginning of year			582	1,181
Cash and cash equivalents, end of period	1,071	452	1,071	452
All Other Subsidiaries [Member]
Cash flows from operating activities:
Net income	167	168	500	497
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income taxes			(1)	1
Changes in operating assets and liabilities:
Accounts and other receivables			(2)
Inventories			(14)
Accounts payable and accrued liabilities			(877)	(20)
Income taxes			(2)
Other current assets			(11)
Net cash provided by (used in) operating activities			(407)	478
Cash flows from investing activities:
Business acquisition, net of cash acquired			(135)
Net cash (used in) investing activities			(135)
Cash flows from financing activities:
Dividends paid				(550)
Proceeds from issuance of long-term debt			125
Contribution from parent			50
Net cash (used in) provided by financing activities			175	(550)
Change in cash and cash equivalents			(367)	(72)
Cash and cash equivalents, beginning of year			817	719
Cash and cash equivalents, end of period	450	647	450	647
Total Consolidating Adjustments [Member]
Cash flows from operating activities:
Net income	(454)	(435)	(1,296)	(1,303)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity income from subsidiaries	454	435	1,296	1,303
Changes in operating assets and liabilities:
Accounts and other receivables			(875)
Accounts payable and accrued liabilities			875
Other assets			125
Return on investment in subsidiaries			(1,021)	(2,746)
Net cash provided by (used in) operating activities			(896)	(2,746)
Cash flows from investing activities:
Investment in subsidiary			50
Net cash (used in) investing activities			50
Cash flows from financing activities:
Dividends paid			1,021	2,746
Proceeds from issuance of long-term debt			(125)
Contribution from parent			(50)
Net cash (used in) provided by financing activities			$ 846	$ 2,746