Stock-Based Compensation, Common Stock Repurchases and Dividends (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			1 Months Ended	3 Months Ended		12 Months Ended					12 Months Ended		1 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 30, 2008 Stock Options	Dec. 31, 2012 Stock Options	Mar. 31, 2008 Stock Options	Dec. 31, 2012 Stock Options	Dec. 31, 2011 Stock Options	Dec. 31, 2010 Stock Options	Dec. 31, 2012 Restricted Stock	Dec. 31, 2011 Restricted Stock	Dec. 31, 2012 2007 Stock Incentive Plan Stock Options	Dec. 31, 2012 Director 2007 Stock Incentive Plan Stock Options	Nov. 30, 2012 Newly Hired Executive Officers Non-Qualified Options	Oct. 30, 2011 Newly Hired Executive Officers Non-Qualified Options	Apr. 30, 2009 Newly Hired Executive Officers Non-Qualified Options	Dec. 31, 2012 Newly Hired Executive Officers Non-Qualified Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares available for future grant												143,189
Award vesting period												4 years	6 months
Termination period from the date of grant				7 years		10 years						7 years	10 years				7 years
Granted non-qualified options to purchase shares of common stock	528,000	587,000	284,000											100,000	150,000	200,000
Expected dividend yield					0.00%
Total stock option compensation expense not yet recognized								$ 2,727			$ 1,270
Weighted-average period for recognition of cost not yet recognized							2 years 9 months 12 days			2 years 7 months 6 days
Net tax impact of share-based compensation reduction in additional paid-in capital							$ 214	$ 19	$ 114
Common stock repurchase shares authorized	3,500,000