Other Items - Accumulated other comprehensive loss (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (7.6)
Tax (expense)	(49.1)		(122.4)		(108.8)
Total other comprehensive (loss)	(6.1)		7.1		(8.5)
Balance at end of period	(13.7)		(7.6)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(5.0)		(13.2)		(5.4)
Tax (expense)	2.7	[1]	(2.7)	[1]	0	[1]
Total other comprehensive (loss)	(13.3)	[1]	10.9	[1]	(7.8)	[1]
Balance at end of period	(15.6)		(5.0)		(13.2)
Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(2.7)		(1.6)		(0.9)
Net change from period revaluations	5.2		2.7		0.3
Tax (expense)	(1.5)	[2]	(0.5)	[2]	(0.1)	[2]
Total other comprehensive income (loss) before reclassifications, net of tax	3.7		2.2		0.2
Total amount reclassified from accumulated other comprehensive loss, net of tax	(2.4)		(3.3)		(0.9)
Total other comprehensive (loss)	1.3		(1.1)		(0.7)
Balance at end of period	(1.4)		(2.7)		(1.6)
Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	0		0		0
Net change from period revaluations	5.2		0		0
Tax (expense)	(2.0)	[2]	0	[2]	0	[2]
Balance at end of period	3.2		0		0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax (expense)	0.8	[2]	0.7	[2]	0.6	[2]
Net amount reclassified to earnings	$ (3.2)	[3]	$ (4.0)	[3]	$ (1.5)	[3]

[1] In 2013 and 2011, there were no tax impacts related to rate changes and no amounts were reclassified to earnings. In 2012, a $2.7 million tax impact was recorded.

[2] These amounts were included in the income tax provision on the accompanying Consolidated Statements of Income.

[3] This amount was included in interest expense, net on the accompanying Consolidated Statements of Income.