Accumulated Other Comprehensive Income / (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	$ 18.0	$ (44.5)	$ 11.6	$ (6.8)
Other comprehensive income before reclassifications	17.7	2.4	23.0	(35.5)
Amounts reclassified from accumulated other comprehensive income - net of tax	1.2	0.6	2.3	0.8
Net current-period other comprehensive income	18.9	3.0	25.3	(34.7)
Balance at the end of the period	36.9	(41.5)	36.9	(41.5)
Foreign Currency Translation
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	20.9	(38.4)	11.4	(1.2)
Other comprehensive income before reclassifications	16.9	1.5	26.4	(34.8)
Amounts reclassified from accumulated other comprehensive income - net of tax				(0.9)
Net current-period other comprehensive income	16.9	1.5	26.4	(35.7)
Balance at the end of the period	37.8	(36.9)	37.8	(36.9)
Other
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(2.9)	(6.1)	0.2	(5.6)
Other comprehensive income before reclassifications	0.8	0.9	(3.4)	(0.7)
Amounts reclassified from accumulated other comprehensive income - net of tax	1.2	0.6	2.3	1.7
Net current-period other comprehensive income	2.0	1.5	(1.1)	1.0
Balance at the end of the period	$ (0.9)	$ (4.6)	$ (0.9)	$ (4.6)