Commitments and Contingencies (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Changes in the accrued product quality issue
Total accrued product quality issue as of December 31, 2011	$ 7.5
Estimated expense for expected product quality claims	0.7
Product quality claims	(1.7)
Total accrued product quality issue as of June 30, 2012	$ 6.5