Stock-Based Compensation Plans (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance	3,469
Stock grants vesting period, minimum (in years)	three
Stock grants vesting period, maximum (in years)	five
Description and terms of 2003 stock incentive plan	Under the 2003 Stock Plan, an aggregate of 3,469 shares of common stock were reserved for issuance. Of this amount, stock grants count against the total shares available under the 2003 Stock Plan as 2.7 shares for every one share issued, while options (and stock appreciation rights ("SAR") settled in shares) count against the total shares available as one share for every one share issued on the exercise of an option (or SAR). The exercise price of each option granted under the 2003 Stock Plan may not be less than the market price of the Company's common stock on the date of the option grant and all options may have a maximum life of ten years. Participants receiving restricted stock grants are generally eligible to vote such shares and receive dividends on such shares. Substantially all stock option and restricted stock grants are subject to annual vesting provisions (generally three to five years) as determined by the compensation committee overseeing the 2003 Stock Plan.
Maximum life of all options (in years)	ten
Total intrinsic value of stock options exercised	$ 5,525	$ 2,827	$ 0
Maximum number of shares issuable under the ESPP	300
Employee stock purchase plan description, compensation expense	198	384	281
Percentage of share purchase price	85.00%
Discount on the share purchases	15.00%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to stock options	379	317	1,198
Unrecognized compensation cost related to unvested stock options	364
Unrecognized compensation costs, weighted-average period of recognition, years	1.7
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock options	1,861
Unrecognized compensation costs, weighted-average period of recognition, years	1.7
Total compensation expense relating to the restricted stock	2,004	2,309	3,040
Total Intrinsic value of restricted shares vested	$ 4,246	$ 3,561	$ 2,281