Income Taxes - Effective tax rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Provision for tax at statutory rate (as a percent)	35.00%	35.00%	35.00%
Tax rate difference on foreign income (as a percent)	(5.60%)	(5.50%)	(5.80%)
State and local taxes - net (as a percent)	0.70%	0.30%	0.30%
Tax impact of fluctuations in Mexican Pesos to US Dollar	(0.50%)	2.40%	2.90%
Net impact of U.S. foreign tax credits	0.30%	(2.30%)	0.90%
Net impact of valuation allowance in Argentina	2.00%	1.00%
Net impact of transition tax	2.70%
Net impact of U.S. deferred tax remeasurement	(4.90%)
Net impact of provision for taxes on unremitted earnings	4.30%	0.50%
Other items - net (as a percent)	(1.90%)	(1.50%)	(2.10%)
Provision at effective tax rate (as a percent)	30.80%	33.10%	31.20%
Tax impact of change in Mexican Pesos to US Dollars	$ 4.0	$ 18.0	$ 17.0
Tax impact of change in Mexican Pesos to US Dollars, percentage points	0.50%	2.40%	2.90%
Pre-tax gain on foreign currency exchange amounts	$ 0.0	$ 0.0
Increase in valuation allowance of foreign subsidiary net deferred tax assets	$ 16.0	$ 7.0
Percentage increase in valuation allowance of foreign subsidiary net deferred tax assets	2.0	1.0
Net tax impact of US / Canada settlement	$ 10.0	$ 24.0
Net tax impact of US / Canada settlement percentage	(1.30%)	3.20%
Net tax impact of US / Canada settlement reserve based on effective tax rate in 2016		$ 7.0
Net tax impact of US / Canada settlement based on effective tax rate in 2016 percentage		1.00%
Income tax provision (benefit) that offset income tax indemnification income	$ 7.0	$ 4.0
Undistributed earnings on foreign subsidiaries tax provision	33.0
Undistributed earnings of foreign subsidiaries	2,700.0
Balance at January 1	86.0	12.0
Additions for tax positions related to prior years		72.0
Reductions for tax positions related to prior years		(9.0)
Additions based on tax positions related to the current year	12.0	12.0
Settlements	(58.0)
Reductions related to a lapse in the statute of limitations	(1.0)	(1.0)
Balance at December 31	39.0	86.0	$ 12.0
Unrecognized tax benefit that, if recognized, could affect the effective tax rate in future periods	15.0
Remaining unrecognized tax benefits	24.0
Unrecognized tax benefit, income tax receivable	23.0
Unrecognized tax foreign benefit that would be created as part of Canada and US process	1.0
Settlement of claims with Canadian tax authority	63.0
Interest expense accrued, net of interest income	$ 2.0	9.0
MEXICO
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Provision for tax at statutory rate (as a percent)	30.00%
CANADA
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Provision for tax at statutory rate (as a percent)	25.00%
PAKISTAN
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Provision for tax at statutory rate (as a percent)	30.00%
BRAZIL
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Provision for tax at statutory rate (as a percent)	34.00%
2016
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Net tax impact of US / Canada settlement income tax expense		70.0
Net tax impact of US / Canada settlement income tax benefit		$ 46.0
Net tax impact of US / Canada settlement percentage		3.20%
Akzo Nobel NV
Reconciliation of the US federal statutory tax rate to the Company's effective tax rate
Income tax provision (benefit) that offset income tax indemnification income			(4.0)	$ 7.0
Pre-acquisition audit result adjustment, tax			(3.0)	5.0
Pre-acquisition audit result adjustment, interest			$ (1.0)	$ 2.0
Pre-acquisition audit result adjustment (as a percent)			(0.70%)	1.30%