Stock-Based Compensation - Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended						9 Months Ended					3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2007 2005 Stock Plan [Member]	Sep. 30, 2012 2011 Equity Incentive Award Plan [Member]	Dec. 31, 2011 2011 Equity Incentive Award Plan [Member]	May 09, 2011 2011 Equity Incentive Award Plan [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Restricted Stock [Member]	Sep. 30, 2011 Restricted Stock [Member]	Sep. 30, 2012 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2012 Performance Shares Awards [Member]	Sep. 30, 2012 Performance Shares Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issue (in shares)			2,500,000			3,000,000
Shares available for future issuance (in shares)				2,704,672	3,336,614
Award vesting percentage per year (as a percent)									25.00%		25.00%
Award vesting period							4 years
Contractual term							10 years
Weighted average assumptions, expected volatility factor							46.20%					39.00%
Weighted average assumptions, expected dividend yield							0.00%					0.00%
Weighted average assumptions, expected term							6 years 3 months					2 years 8 months 23 days
Weighted average assumptions, risk-free interest rate							2.00%					0.45%
Weighted-average fair value for stock options granted								$ 5.72
Grants in period (in shares)							0
Share-based compensation cost	$ 3.0	$ 0.4
Potential vesting percentage, minimum													0.00%
Potential vesting percentage, maximum													200.00%
Issuance window after award vesting													60 days
Total unrecognized compensation cost									$ 7.2	$ 1.5		$ 7.5	$ 7.5
Total unrecognized cost, period for recognition (in years)									3 years 3 months 18 days	2 years 9 months 18 days			2 years 3 months