Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Foreign Currency Translation:
Balance at beginning of period	$ 175.8	$ 167.5	$ 158.9
Other comprehensive income	(14.7)	8.3	8.6
Balance at end of period	161.1	175.8	167.5
Unrealized Losses on Cash Flow Hedges
Balance at beginning of period	(3.0)	(3.5)	(4.8)
Other comprehensive income	(0.3)	(2.1)	(1.2)
Realized (gain) loss on reclassification	2.2	2.6	2.5
Balance at end of period	(1.1)	(3.0)	(3.5)
Pension Liability Adjustment
Balance at beginning of period	(20.4)	(10.5)	(16.3)
Other comprehensive income	2.9	(9.9)	5.8
Balance at end of period	(17.5)	(20.4)	(10.5)
Accumulated Other Comprehensive Income
Balance at beginning of period	152.4	153.5	137.8
Other comprehensive income	(12.1)	(3.7)	13.2
Realized (gain) loss on reclassification	2.2	2.6	2.5
Balance at end of period	$ 142.5	$ 152.4	$ 153.5