Retirement and Postemployment Benefits (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 29, 2011	May 30, 2010	May 31, 2009
Defined Benefit Plan Assumed Health Care Cost Trend Rates [Abstract]
Health care cost trend rate for next year	8.50%	9.00%
Year that the rate reaches the ultimate trend rate	2019	2019
Rate to which the cost trend rate is assumed to decline (ultimate rate)	5.20%	5.20%
Defined Benefit Plan Effect Of One Percentage Point Change In Assumed Health Care Cost Trend Rates [Abstract]
Effect on the aggregate of the service and interest cost components in fiscal 2012	$ 6.2
Effect on the other postretirement accumulated benefit obligation as of May 29, 2011	82.4
Effect on the aggregate of the service and interest cost components in fiscal 2012	(5.4)
Effect on the other postretirement accumulated benefit obligation as of May 29, 2011	(73.6)
Explanation of significant change in benefit obligation or plan assets not apparent from other required disclosures	The Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the Act) was signed into law in March 2010. The Act codifies health care reforms with staggered effective dates from 2010 to 2018. Estimates of the future impacts of several of the Act’s provisions are incorporated into our postretirement benefit liability including the elimination of lifetime maximums and the imposition of an excise tax on high cost health plans. These changes resulted in a $24.0 million increase in our postretirement benefit liability in fiscal 2010.
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Actual return on assets			1,100.0
Defined Benefit Plan Change In Benefit Obligation Roll Forward [Abstract]
Accumulated Benefit Obligation	3,991.6	3,620.3
Defined Benefit Plan Amounts Recognized In Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	1,509.5	1,611.0
Prior service costs (credits)	20.7	47.5
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Pension and Other Postretirement Plans, Net of Tax, Total	1,530.2	1,658.5
Defined Benefit Plan Assets Fair Value Abstract
Actual Return Attributable To Unrealized Gain Loss On Plan Assets Still Held	96.8
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Number Of fiscal years presented	two
Target allocation percentage of assets fixed income funds	30.00%
Target allocation percentage of assets real assets	10.00%
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
2012	5.0
2013	5.5
2014	6.0
2015	6.5
2016	7.1
2017-2021	38.9
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Description Of Defined Contribution Pension And Other Postretirement Plans	We matched a percentage of employee contributions to the General Mills Savings Plan with a base match plus a variable year-end match that depended on annual results.
Net assets money purchase plan	18.1	16.8
Cost recognized	41.8	64.5	59.5
ESOP number of allocated shares	11.2	11.9
ESOP compensation expense	0	53.7	50.6
Common stock held by ESOP and company stock fund	648.1	610.3
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	3,529.8	3,157.8
Actual return on assets	688.9	535.9
Employer contributions	220.7	17.1
Plan participant contributions	4.1	3.5
Acquisitions and divestitures	0	0
Benefits Payments	(188.2)	(182.6)
Foreign currency	8.7	(1.9)
Fair value at end of year	4,264.0	3,529.8	3,157.8
Defined Benefit Plan Change In Benefit Obligation Roll Forward [Abstract]
Benefit obligation at beginning of year	4,030.0	3,167.3
Interest cost	230.9	230.3
Plan amendment	0	25.8
Curtailment/other	0	0
Medicare Part D reimbursements	0	0
Actuarial loss (gain)	271.2	716.4
Benefits payments	(188.2)	(182.6)
Foreign currency	9.0	(1.6)
Projected benefit obligation at end of year	4,458.4	4,030.0	3,167.3
Plan assets less than benefit obligation as of fiscal year end	(194.4)	(500.2)
Defined Benefit Plan Amounts Recognized In Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	1,313.9	1,369.9
Prior service costs (credits)	35.8	41.3
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Pension and Other Postretirement Plans, Net of Tax, Total	1,349.7	1,411.2
Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets [Abstract]
Projected benefit obligation	335.1	299.6
Accumulated benefit obligation	280.6	252.5
Plan assets at fair value	9.0	17.3
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service cost	101.4	70.9	76.5
Interest Cost	230.9	230.3	215.4
Expected return on plan assets	(408.5)	(400.1)	(385.8)
Amortization of losses	81.4	8.4	7.8
Amortization of prior service costs (credits)	9.0	6.9	7.4
Other Adjustments	0	0	0
Net (income) expense	14.2	(83.6)	(78.7)
Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]
Amortization of losses	108.2
Amortization of prior service costs (credits)	8.6
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	5.45%	5.85%
Rate of salary increases	4.92%	4.93%
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount rate	5.85%	7.49%	6.88%
Rate of salary increases	4.93%	4.92%	4.93%
Expected long-term rate of return on plan assets.	9.53%	9.55%	9.55%
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Fixed income	23.90%	22.40%
Real assets	13.60%	13.20%
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
2012	204.8
2013	213.8
2014	223.3
2015	233.2
2016	243.8
2017-2021	1,402.3
Defined Benefit Pension Plans [Member] | Level 1 [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	2,116.1	1,675.8
Defined Benefit Pension Plans [Member] | Level 1 [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	1,052.5	744.5
Defined Benefit Pension Plans [Member] | Level 1 [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	794.7	700.0
Defined Benefit Pension Plans [Member] | Level 1 [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	113.0	72.4
Defined Benefit Pension Plans [Member] | Level 1 [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Defined Benefit Pension Plans [Member] | Level 1 [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	155.9	158.9
Defined Benefit Pension Plans [Member] | Level 2 [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	1,222.0	1,038.3
Defined Benefit Pension Plans [Member] | Level 2 [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	900.2	716.6
Defined Benefit Pension Plans [Member] | Level 2 [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	174.4	206.0
Defined Benefit Pension Plans [Member] | Level 2 [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	95.2	75.8
Defined Benefit Pension Plans [Member] | Level 2 [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	52.2	39.9
Defined Benefit Pension Plans [Member] | Level 2 [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Defined Benefit Pension Plans [Member] | Level 3 [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	815.7	703.8
Fair value at end of year	925.9	815.7
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	1.5	0
Purchases, Sales Issuances, and Settlements (Net)	(36.4)	40.5
Actual return on plan assets still held	145.1	71.4
Defined Benefit Pension Plans [Member] | Level 3 [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	512.8	423.9
Fair value at end of year	568.5	512.8
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	2.4	0
Purchases, Sales Issuances, and Settlements (Net)	(48.1)	17.0
Actual return on plan assets still held	101.4	71.9
Defined Benefit Pension Plans [Member] | Level 3 [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	3.9	4.2
Fair value at end of year	0.2	3.9
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	(0.9)	0
Purchases, Sales Issuances, and Settlements (Net)	(4.3)	(1.2)
Actual return on plan assets still held	1.5	0.9
Defined Benefit Pension Plans [Member] | Level 3 [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	298.7	275.2
Fair value at end of year	356.9	298.7
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	0	0
Purchases, Sales Issuances, and Settlements (Net)	16.0	25.0
Actual return on plan assets still held	42.2	(1.5)
Defined Benefit Pension Plans [Member] | Level 3 [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	0.3	0.5
Fair value at end of year	0.3	0.3
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	0	0
Purchases, Sales Issuances, and Settlements (Net)	0	(0.3)
Actual return on plan assets still held	0	0.1
Defined Benefit Pension Plans [Member] | Level 3 [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Defined Benefit Pension Plans [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	2,521.2	1,973.9
Defined Benefit Pension Plans [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	969.3	909.9
Defined Benefit Pension Plans [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	565.1	446.9
Defined Benefit Pension Plans [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	52.5	40.2
Defined Benefit Pension Plans [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	155.9	158.9
Defined Benefit Pension Plans [Member] | United States Equity Securities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Defined Benefit Plan Equity Securities	30.10%	32.60%
Defined Benefit Pension Plans [Member] | International Equity Securities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Defined Benefit Plan Equity Securities	18.90%	17.10%
Defined Benefit Pension Plans [Member] | Private Equities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Defined Benefit Plan Equity Securities	13.50%	14.70%
United States Pension Plans Of US Entity Defined Benefit [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Employer contributions	200.0
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	284.3	235.6
Actual return on assets	60.7	41.0
Employer contributions	0.1	0.1
Plan participant contributions	11.8	11.3
Acquisitions and divestitures	0	0
Benefits Payments	(3.1)	(3.7)
Foreign currency	0	0
Fair value at end of year	353.8	284.3	235.6
Defined Benefit Plan Change In Benefit Obligation Roll Forward [Abstract]
Benefit obligation at beginning of year	1,060.6	852.0
Interest cost	60.1	61.6
Plan amendment	(35.3)	7.5
Curtailment/other	0	0
Medicare Part D reimbursements	4.5	4.7
Actuarial loss (gain)	2.0	168.1
Benefits payments	(56.9)	(57.5)
Foreign currency	0.3	0
Projected benefit obligation at end of year	1,065.8	1,060.6	852.0
Plan assets less than benefit obligation as of fiscal year end	(712.0)	(776.3)
Defined Benefit Plan Amounts Recognized In Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	181.3	225.2
Prior service costs (credits)	(20.7)	(1.0)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Pension and Other Postretirement Plans, Net of Tax, Total	160.6	224.2
Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets [Abstract]
Projected benefit obligation	0	0
Accumulated benefit obligation	1,065.8	1,060.6
Plan assets at fair value	353.8	284.3
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service cost	18.7	12.9	14.2
Interest Cost	60.1	61.6	61.2
Expected return on plan assets	(33.2)	(29.2)	(30.0)
Amortization of losses	14.4	2.0	7.2
Amortization of prior service costs (credits)	(0.6)	(1.6)	(1.4)
Other Adjustments	0	0	0
Net (income) expense	59.4	45.7	51.2
Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]
Amortization of losses	14.4
Amortization of prior service costs (credits)	(3.4)
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	5.35%	5.80%
Rate of salary increases	0.00%	0.00%
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount rate	5.80%	7.45%	6.90%
Rate of salary increases	0.00%	0.00%	0.00%
Expected long-term rate of return on plan assets.	9.33%	9.33%	9.35%
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Fixed income	30.10%	28.10%
Real assets	6.30%	6.40%
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
2012	58.6
2013	62.6
2014	64.6
2015	66.6
2016	39.6
2017-2021	387.7
Other Postretirement Benefit Plans [Member] | Level 1 [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	35.7	39.7
Other Postretirement Benefit Plans [Member] | Level 1 [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	13.5	10.1
Other Postretirement Benefit Plans [Member] | Level 1 [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	1.8	1.1
Other Postretirement Benefit Plans [Member] | Level 1 [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0.1
Other Postretirement Benefit Plans [Member] | Level 1 [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Other Postretirement Benefit Plans [Member] | Level 1 [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	20.4	28.4
Other Postretirement Benefit Plans [Member] | Level 2 [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	278.0	202.6
Other Postretirement Benefit Plans [Member] | Level 2 [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	131.0	81.4
Other Postretirement Benefit Plans [Member] | Level 2 [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	55.9	46.1
Other Postretirement Benefit Plans [Member] | Level 2 [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	7.2	3.7
Other Postretirement Benefit Plans [Member] | Level 2 [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	83.9	71.4
Other Postretirement Benefit Plans [Member] | Level 2 [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Other Postretirement Benefit Plans [Member] | Level 3 [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	42.0	42.3
Fair value at end of year	40.1	42.0
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	0	0
Purchases, Sales Issuances, and Settlements (Net)	(7.4)	(2.1)
Actual return on plan assets still held	5.5	1.8
Other Postretirement Benefit Plans [Member] | Level 3 [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	25.7	23.8
Fair value at end of year	26.3	25.7
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	0	0
Purchases, Sales Issuances, and Settlements (Net)	(3.7)	(1.5)
Actual return on plan assets still held	4.3	3.4
Other Postretirement Benefit Plans [Member] | Level 3 [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	1.7	1.5
Fair value at end of year	0.2	1.7
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	0	0
Purchases, Sales Issuances, and Settlements (Net)	(1.5)	0
Actual return on plan assets still held	0	0.2
Other Postretirement Benefit Plans [Member] | Level 3 [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at beginning of year	14.6	17.0
Fair value at end of year	13.6	14.6
Defined Benefit Plan Assets Fair Value Abstract
Transfers In/(Out)	0	0
Purchases, Sales Issuances, and Settlements (Net)	(2.2)	(0.6)
Actual return on plan assets still held	1.2	(1.8)
Other Postretirement Benefit Plans [Member] | Level 3 [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Other Postretirement Benefit Plans [Member] | Level 3 [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	0	0
Other Postretirement Benefit Plans [Member] | Equity [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	170.8	117.2
Other Postretirement Benefit Plans [Member] | Fixed income [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	57.9	48.9
Other Postretirement Benefit Plans [Member] | Real asset investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	20.8	18.4
Other Postretirement Benefit Plans [Member] | Other investments [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	83.9	71.4
Other Postretirement Benefit Plans [Member] | Cash and accruals [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Fair value at end of year	20.4	28.4
Other Postretirement Benefit Plans [Member] | United States Equity Securities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Defined Benefit Plan Equity Securities	37.60%	37.30%
Other Postretirement Benefit Plans [Member] | International Equity Securities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Defined Benefit Plan Equity Securities	18.70%	18.30%
Other Postretirement Benefit Plans [Member] | Private Equities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Defined Benefit Plan Equity Securities	7.30%	9.90%
Postemployment Benefit Plans [Member]
Defined Benefit Plan Change In Fair Value Of Plan Assets Roll Forward [Abstract]
Plan participant contributions	0	0
Defined Benefit Plan Change In Benefit Obligation Roll Forward [Abstract]
Benefit obligation at beginning of year	130.3	112.5
Interest cost	5.1	5.6
Plan amendment	0	0
Curtailment/other	4.2	10.6
Medicare Part D reimbursements	0	0
Actuarial loss (gain)	(0.5)	11.8
Benefits payments	(16.1)	(17.6)
Foreign currency	0.3	0.2
Projected benefit obligation at end of year	131.3	130.3	112.5
Plan assets less than benefit obligation as of fiscal year end	(131.3)	(130.3)
Defined Benefit Plan Amounts Recognized In Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	14.3	15.9
Prior service costs (credits)	5.6	7.2
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Pension and Other Postretirement Plans, Net of Tax, Total	19.9	23.1
Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets [Abstract]
Projected benefit obligation	0	0
Accumulated benefit obligation	131.3	130.3
Plan assets at fair value	0	0
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service cost	8.0	7.2	6.5
Interest Cost	5.1	5.7	4.9
Expected return on plan assets	0	0	0
Amortization of losses	2.1	1.0	1.0
Amortization of prior service costs (credits)	2.4	2.4	2.2
Other Adjustments	4.2	10.6	8.4
Net (income) expense	21.8	26.9	23.0
Defined Benefit Plan Amounts That Will Be Amortized From Accumulated Other Comprehensive Income Loss In Next Fiscal Year [Abstract]
Amortization of losses	1.8
Amortization of prior service costs (credits)	2.1
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation [Abstract]
Discount rate	4.77%	5.12%
Rate of salary increases	4.92%	4.93%
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Discount rate	5.12%	7.06%	6.64%
Rate of salary increases	4.93%	4.93%	4.93%
Expected long-term rate of return on plan assets.	0.00%	0.00%	0.00%
Defined Benefit Plan Estimated Future Benefit Payments [Abstract]
2012	18.4
2013	17.3
2014	16.3
2015	15.1
2016	14.4
2017-2021	$ 66.6
United States Equity Securities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Target Allocation Percentage Of Assets Equity Securities	30.00%
International Equity Securities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Target Allocation Percentage Of Assets Equity Securities	20.00%
Private Equities
Defined Benefit Plan Weighted Average Asset Allocations [Abstract]
Target Allocation Percentage Of Assets Equity Securities	10.00%