Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income	$ 1,116	$ 1,029	$ 948
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	37	35	32
Pension, health and life insurance contributions	(42)	(32)	(37)
Pension, health and life insurance benefits expense	28	30	46
Deferred income taxes	(15)	1	(9)
Share-based compensation	16	8	5
Excess tax benefits from share-based arrangements	(4)	(2)	(1)
Changes in operating assets and liabilities:
Accounts and other receivables	1	5	12
Inventories		4	(26)
Accounts payable and accrued liabilities	(33)	(46)	56
Settlement costs	91	78	8
Income taxes	(6)	(34)
Other current assets	(10)	(2)
Other assets	4	17	(4)
Other			7
Net cash provided by operating activities	1,183	1,091	1,037
Cash flows from investing activities:
Additions to plant and equipment	(56)	(40)	(51)
Cash flows from financing activities:
Shares repurchased	(1,586)	(716)	(910)
Proceeds from issuance of long-term debt	750	1,000	750
Dividends paid $3.84, $4.25 and $5.20 per share for the year 2009, 2010 and 2011 respectively	(723)	(645)	(631)
Debt issuance costs	(9)	(13)	(5)
Proceeds from exercise of stock options	8		2
Excess tax benefits from share-based arrangements	4	2	1
Net cash used in financing activities	(1,556)	(372)	(793)
Change in cash and cash equivalents	(429)	679	193
Cash and cash equivalents, beginning of year	2,063	1,384	1,191
Cash and cash equivalents, end of year	1,634	2,063	1,384
Cash paid for income taxes	671	637	563
Cash paid for interest, net of cash received from interest rate swaps of $24 in 2011, $24 in 2010 and $6 in 2009	$ 109	$ 79	$ 28