Stock-Based Compensation - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Restricted Stock and Restricted Stock Units	Dec. 31, 2011 Restricted Stock and Restricted Stock Units	Dec. 31, 2012 Stock Options	Dec. 31, 2011 Stock Options	Dec. 31, 2010 Stock Options	Dec. 31, 2012 Performance Share Awards	Dec. 31, 2007 2005 Stock Plan	Dec. 31, 2012 2011 Equity Incentive Award Plan	Dec. 31, 2011 2011 Equity Incentive Award Plan	May 09, 2011 2011 Equity Incentive Award Plan
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)											2,689,490	3,336,614
Award vesting percentage, per year (as a percent)				25.00%
Award vesting period						4 years
Contractual term						10 years
Weighted average assumptions, expected volatility factor							46.25%	51.60%	39.00%
Weighted average assumptions, expected dividend yield							0.00%	0.00%	0.00%
Weighted average assumptions, expected term							6 years 3 months	6 years 3 months	2 years 8 months 19 days
Weighted average assumptions, risk-free interest rate							2.03%	2.12%	0.44%
Share-based compensation cost	$ 4,327,000	$ 530,000	$ 569,000
Share-based compensation cost, tax benefit recognized in income	1,600,000	189,000	400,000
Total unrecognized compensation cost				$ 6,800,000	$ 1,300,000				$ 6,900,000
Total unrecognized cost, period for recognition (in years)				3 years 1 month 6 days	2 years 7 months 6 days				2 years
Potential vesting percentage, minimum									0.00%
Potential vesting percentage, minimum									200.00%
Issuance window after award vesting									60 days