Stock-Based Compensation Plans (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011 Y
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance	3,469
Stock-based compensation arrangement maximum assumption expected period, years		10
Share-based compensation arrangement by share-based payment award vesting period, minimum (in years)	three
Share-based compensation arrangement by share-based payment award vesting period, maximum (in years)	five
Description and terms of 2003 incentive stock plan	Incentive stock awards are granted under the Company's 2003 Incentive Stock Plan, as amended and restated in October 2008 (the "2003 Stock 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.
Stock grants counted against the total shares for every share issued	2.7
Maximum number of shares issuable under the ESPP	300
Employee stock purchase plan description, compensation expense	$ 48	$ 84
Percentage of share purchase price	85.00%
Discount on the share purchases	15.00%
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to stock options	110	93
Unrecognized compensation cost related to unvested stock options	687
Unrecognized compensation costs, weighted average period of recognition, years	2.3
Total intrinsic value of stock options exercised	4,464	3,341
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock options	3,830
Unrecognized compensation costs, weighted average period of recognition, years	2.3
Total compensation expense relating to the restricted stock	$ 559	$ 500

Stock-Based Compensation Plans (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified

3 Months Ended

Mar. 31, 2012

Mar. 31, 2011

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares of common stock reserved for issuance

3,469

Stock-based compensation arrangement maximum assumption expected period, years

Share-based compensation arrangement by share-based payment award vesting period, minimum (in years)

three

Share-based compensation arrangement by share-based payment award vesting period, maximum (in years)

five

Description and terms of 2003 incentive stock plan

Incentive stock awards are granted under the Company's 2003 Incentive Stock Plan, as amended and restated in October 2008 (the "2003 Stock 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.

Stock grants counted against the total shares for every share issued

2.7

Maximum number of shares issuable under the ESPP

300

Employee stock purchase plan description, compensation expense

$ 48

$ 84

Percentage of share purchase price

85.00%

Discount on the share purchases

15.00%

Stock Option [Member]