Income tax (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract]
U.S. income before income taxes	$ 229.5	$ 188.6	$ 221.6
Non-U.S. income before income taxes	49.1	103.6	105.7
Income from continuing operations before income taxes	278.6	292.2	327.3
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	60.3	49.3	70.9
Foreign	30.5	31.2	28.7
State and local	5.3	0.9	9.9
Total current tax expense	96.1	81.4	109.5
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	16.4	13.3	2.0
Foreign	(10.2)	5.1	5.7
State and local	2.5	5.1	0.4
Total deferred tax expense	8.7	23.5	8.1
Provision for income taxes	104.8	104.9	117.6
Components of Deferred Tax Assets [Abstract]
Accounts receivable, principally due to allowances for returns and doubtful accounts	8.7	9.5
Inventories, principally due to additional costs inventories for tax purposes	25.7	25.9
Employee compensation and benefits accrued for financial reporting purposes	127.8	141.2
Foreign net operating losses	25.0	22.5
Foreign tax credits	9.0	9.0
Other	8.6	4.6
Total deferred tax assets	204.8	212.7
Less valuation allowance	(36.6)	(31.6)
Total deferred tax assets after valuation allowance	168.2	181.1
Components of Deferred Tax Liabilities [Abstract]
Plant and equipment, principally due to differences in depreciation, capitalized interest, and capitalized overhead	138.6	149.0
Goodwill and intangible assets, principally due to differences in amortization	145.8	129.2
Other	0	3.5
Total deferred tax liabilities	284.4	281.7
Deferred tax liabilities, net	116.2	100.6
Deferred Tax Assets, Net, Classification [Abstract]
Deferred tax assets (included in prepaid expense and other current assets)	82.1	74.9
Deferred tax liabilities	198.3	175.5
Net deferred tax liabilities	116.2	100.6
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed expected tax expense on income before taxes at federal statutory rate	97.5	102.3	114.6
Increase (Decrease) Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
State and local income taxes net of federal income tax benefit	5.0	3.9	6.7
Foreign tax rate differential	3.1	(0.6)	(3.4)
Manufacturing tax benefits	(5.2)	(4.2)	(5.8)
Other	4.4	3.5	5.5
Actual income tax expense	104.8	104.9	117.6
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
Increase (Decrease) Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
State and local income taxes net of federal income tax benefit	1.80%	1.30%	2.00%
Foreign tax rate differential	1.10%	(0.20%)	(1.00%)
Manufacturing tax benefits	(1.90%)	(1.40%)	(1.80%)
Other	1.60%	1.20%	1.70%
Effective tax rate	37.60%	35.90%	35.90%
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	25.6	24.0
Additions based on tax positions related to the current year	2.3	2.0
Additions for tax positions of prior years	3.4	5.9
Reductions for tax positions of prior years	(0.4)	(1.2)
Reductions due to a lapse of the statute of limitations	(5.3)	(1.2)
Settlements	0	(3.9)
Balance at end of year	25.6	25.6	24.0
Operating loss carryforwards	77.4
Operating loss carryforwards subject to expiration	26.5
Foreign tax credit carryforward	9.0
Valuation allowance	36.6	31.6
Undistributed foreign subsidiaries earnings	338.1
Unrecognized tax benefits that would impact effective tax rate	20.4	18.5
Interest and penalties	7.5	6.9
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 4.0