Stock-Based Compensation (Details 3) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended										0 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 2012 Amended Executive Officer Non-Qualified Stock Option Agreement	Dec. 31, 2012 Restricted stock units	Dec. 31, 2011 Restricted stock units	Dec. 31, 2010 Restricted stock units	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2010 Stock options	Mar. 01, 2012 Stock options Senior executive officers
Weighted-average inputs used and fair values determined for stock options granted
Assumed annual dividend rate upon which expected dividend yield is based (in dollars per share)								$ 0.12
Expected volatility (as a percent)								49.30%	51.00%	53.60%
Expected dividend yield (as a percent)								0.70%	0.70%	0.50%
Expected term								4 years 6 months	3 years 6 months	3 years 6 months
Risk-free rate (as a percent)								0.80%	1.40%	1.60%
Weighted-average grant-date fair value (in dollars per share)	$ 7.21	$ 6.02	$ 9.05					$ 7.21	$ 6.02	$ 9.05
Additional disclosure
Stock options awarded (in shares)	756,000	781,000	846,000					756,000	781,000	846,000	275,000
Minimum stock price as a percentage of grant price				150.00%
Restricted stock units
Restricted stock units at the beginning of the period (in shares)					657,825	727,317	609,812
Shares awarded					473,408	305,000	404,000
Shares vested					(350,349)	(314,492)	(235,496)
Shares forfeited					(6,667)	(60,000)	(50,999)
Restricted stock units at the end of the period (in shares)					774,217	657,825	727,317
Outstanding restricted shares vesting schedule
Outstanding restricted stock unit awards, vesting in 2013 (in shares)					368,469
Outstanding restricted stock unit awards, vesting in 2014 (in shares)					259,468
Outstanding restricted stock unit awards, vesting in 2015 (in shares)					146,280
Share-based compensation arrangement by share-based payment award, nonvested options
Nonvested options at the beginning of the period (in shares)	1,374,628	1,142,130	883,398
Granted (in shares)	756,000	781,000	846,000					756,000	781,000	846,000	275,000
Vested (in shares)	(611,659)	(498,507)	(425,107)
Forfeited (in shares)	(67,332)	(49,995)	(162,161)
Nonvested options at the end of the period (in shares)	1,451,637	1,374,628	1,142,130
Nonvested stock options weighted average grant date fair value
Nonvested options at the beginning of the period, weighted-average grant-date fair value (in dollars per share)	$ 7.00	$ 8.31	$ 8.23
Weighted-average grant-date fair value (in dollars per share)	$ 7.21	$ 6.02	$ 9.05					$ 7.21	$ 6.02	$ 9.05
Vested (in dollars per share)	$ 7.03	$ 8.37	$ 9.44
Forfeited (in dollars per share)	$ 7.47	$ 7.89	$ 8.79
Nonvested options at the end of the period, weighted-average grant-date fair value (in dollars per share)	$ 7.08	$ 7.00	$ 8.31
Information related to nonvested options
Total unrecognized compensation cost related to nonvested stock option awards	$ 5.6
Total unrecognized compensation cost, period of recognition	2 years 8 months 12 days