Correction of Errors in Previously Reported Financial Statements (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Condensed consolidated statements of cash flows
Net cash provided by (used in) operating activities	$ 20.9	$ 10.3	$ 39.3	$ 14.0	$ 38.6	$ 48.2
Net cash (used in) investing activities	(15.4)	(9.8)	(29.9)	(23.9)	(54.2)	(48.7)
Net cash provided by (used in) financing activities	(12.3)	(6.3)	(17.0)	0.3	11.4	(0.8)
Effect of foreign currency rate changes on cash		0.2	0.7	0.7	0.9	0.4
Net increase (decrease) in cash and cash equivalents	(6.8)	(5.6)	(6.9)	(8.9)	(3.1)	(0.9)
Cash and cash equivalents at beginning of period	23.7	26.8	23.7	26.8	26.8	27.7
Cash and cash equivalents at end of period	16.9	21.2	16.8	17.9	23.7	26.8
Previously reported [Member]
Condensed consolidated statements of cash flows
Net cash provided by (used in) operating activities	20.6	10.3		13.9	38.6	48.1
Net cash (used in) investing activities	(15.3)	(10.3)		(24.4)	(54.7)	(48.1)
Net cash provided by (used in) financing activities	(12.1)	(6.3)		0.4	11.6	(0.8)
Effect of foreign currency rate changes on cash		0.2		0.7	0.9	0.4
Net increase (decrease) in cash and cash equivalents	(6.8)	(6.1)		(9.4)	(3.6)	(0.4)
Cash and cash equivalents at beginning of period	23.7	27.3	23.7	27.3	27.3	27.7
Cash and cash equivalents at end of period	16.9	21.2		17.9	23.7	27.3
Adjustments [Member]
Condensed consolidated statements of cash flows
Net cash provided by (used in) operating activities	0.3			0.1	0.2	0.1
Net cash (used in) investing activities	(0.1)	0.5		0.5	0.5	(0.6)
Net cash provided by (used in) financing activities	(0.2)			(0.1)	(0.2)
Net increase (decrease) in cash and cash equivalents		0.5		0.5	0.5	(0.5)
Cash and cash equivalents at beginning of period		(0.5)		(0.5)	(0.5)
Cash and cash equivalents at end of period						$ (0.5)