Income Taxes (Tables)

6 Months Ended

Jun. 30, 2014

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of income taxes computed at the U.S. Federal statutory income tax rate to the provision for income taxes is as follows ($ in millions): 

	Three Months Ended										Six Months Ended
	June 30, 2014					June 30, 2013					June 30, 2014					June 30, 2013
	Amount			Percent		Amount			Percent		Amount			Percent		Amount			Percent
Tax provision at U.S. statutory rate	$	11.0		35.0	%	$	14.8		35.0	%	$	22.3		35.0	%	$	29.7		35.0	%
Foreign income tax rate differential	(4.7		)	(15.0	)	(2.0		)	(4.7	)	(7.0		)	(11.0	)	(3.8		)	(4.5	)
Tax effects of foreign legal structure	—			—		(0.4		)	(1.0	)	0.3			0.5		(0.7		)	(0.8	)
Adjustments to valuation allowances	0.9			2.9		—			—		0.9			1.4		—			—
French business tax classified as income tax	0.6			1.9		0.5			1.1		1.1			1.7		1.1			1.3
Other foreign taxes, net	(0.6		)	(1.9	)	0.8			1.8		(1.0		)	(1.5	)	—			—
Other, net	(0.7		)	(2.1	)	0.1			0.2		(0.3		)	(0.5	)	(0.1		)	(0.1	)
Provision for income taxes	$	6.5		20.8	%	$	13.8		32.4	%	$	16.3		25.6	%	$	26.2		30.9	%