Stock-Based Compensation (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Director [Member]
Summary of stock option grants
Grantee Type		Director
No. of Options Granted		8,546
Vesting Period		3 years
Weighted average exercised price		$ 6.11
Weighted Average Grant Date Fair Value		$ 3.95
Director group [Member]
Summary of stock option grants
Grantee Type	Director group	Director group
No. of Options Granted	51,276	58,110
Vesting Period	1 year
Vesting period		1 year or less
Weighted average exercised price	$ 7.53	$ 7.31
Weighted Average Grant Date Fair Value	$ 3.97	$ 4.13
Employee group [Member]
Summary of stock option grants
Grantee Type		Employee group
No. of Options Granted		140,000
Vesting Period		2 years
Weighted average exercised price		$ 6.09
Weighted Average Grant Date Fair Value		$ 3.72
Employee group [Member]
Summary of stock option grants
Grantee Type	Employee group	Employee group
No. of Options Granted	589,750	470,064
Vesting Period	3 years	3 years
Weighted average exercised price	$ 7.53	$ 7.38
Weighted Average Grant Date Fair Value	$ 4.11	$ 4.33