Stock-Based Compensation (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended							1 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2014 compensation_plan	Mar. 31, 2014 The Plans [Member]	Mar. 31, 2013 The Plans [Member]	Mar. 31, 2014 Employee Group [Member]	Mar. 31, 2013 Employee Group [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2014 Director Group [Member]	Mar. 31, 2013 Director Group [Member] 2008 Equity Incentive Plan [Member]	Jun. 30, 2012 Performance Shares [Member] 2006 Management Incentive Plan [Member]	Mar. 31, 2014 Performance Shares [Member] 2006 Management Incentive Plan [Member] executive_officer	Jun. 19, 2012 Performance Shares [Member] 2006 Management Incentive Plan [Member]	Mar. 31, 2014 Restricted Stock and Restricted Stock Units [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2013 Restricted Stock and Restricted Stock Units [Member] Employee Group [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2014 Restricted Stock and Restricted Stock Units [Member] Director [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2014 Stock Options [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2013 Stock Options [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2014 Stock Options [Member] 2008 Equity Incentive Plan [Member]	Mar. 31, 2014 Stock Options [Member] Director [Member] 2008 Equity Incentive Plan [Member]
Stock-Based Compensation (Textual) [Abstract]
Number of stock-based compensation plans	3
Stock options expiration period														7 years
Stock options vesting period				3 years	3 years	1 year						3 years	1 year			3 years	1 year
Stock options award vesting right											vest in equal annual increments over the vesting period			vest in equal annual increments over the vesting period
No. of Options Granted (shares)					5,000		7,122								0
Total of performance units were outstanding and fully vested (shares)									44,076	154,264
Grant date fair value awards								$ 1.2
Percentage of performance units (percent)									60.00%
Percentage of fair market value (percent)									40.00%
Performance units settled in period (shares)									93,664
Number of executive officers that settled performance units in period (executive officers)									4
Number of former executive officers that settled performance units in period (executive officers)									2
Performance units forfeited in period (shares)									16,524
Number of former executive officers that forfeited performance units in period (executive officer)									1
Common stock issued during period (shares)									56,197
Cash payments for shares settled during period									0.2
Selling, general and administrative expenses		1.0	1.3
Unrecognized stock-based compensation expense related to stock options		$ 5.5
Weighted-average period for recognizing stock compensation expense		1 year 8 months 13 days