Stock-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary of stock option grants
No. of Options Granted	707,057
Weighted Average Exercise Price	$ 7.60
Weighted Average Grant Date Fair Value	$ 7.64
Director Group [Member]
Summary of stock option grants
Grantee Type	Director group	Director group	Director group
No. of Options Granted	56,261	65,801	51,276
Vesting Period	1 year or less	1 year or less	1year or less
Weighted Average Exercise Price	$ 7.55	$ 7.23	$ 4.20
Weighted Average Grant Date Fair Value	$ 3.89	$ 4.06	$ 2.53
Director group [Member]
Summary of stock option grants
Grantee Type		Director group
No. of Options Granted		16,237
Vesting Period		3 years
Weighted Average Exercise Price		$ 6.32
Weighted Average Grant Date Fair Value		$ 3.98
Director [Member]
Summary of stock option grants
Grantee Type	Director		Director
No. of Options Granted	8,546		8,546
Vesting Period	3 years		3 years
Weighted Average Exercise Price	$ 7.72		$ 5.39
Weighted Average Grant Date Fair Value	$ 4.25		$ 4.00
Employee group [Member]
Summary of stock option grants
Grantee Type	Employee group	Employee group	Employee group
No. of Options Granted	597,250	140,000	649,010
Vesting Period	3 years	2 years	3 years
Weighted Average Exercise Price	$ 7.54	$ 6.09	$ 4.14
Weighted Average Grant Date Fair Value	$ 4.12	$ 3.72	$ 2.68
Employee group [Member]
Summary of stock option grants
Grantee Type		Employee group
No. of Options Granted		475,064
Vesting Period		3 years
Weighted Average Exercise Price		$ 7.38
Weighted Average Grant Date Fair Value		$ 4.33
Employee inducement [Member]
Summary of stock option grants
Grantee Type	Employee inducement	Employee inducement
No. of Options Granted	45,000	200,000
Vesting Period	3 years
Weighted Average Exercise Price	$ 8.54	$ 5.37
Weighted Average Grant Date Fair Value	$ 4.58	$ 3.13
Employee inducement [Member] | Maximum [Member]
Summary of stock option grants
Vesting Period		4 years
Employee inducement [Member] | Minimum [Member]
Summary of stock option grants
Vesting Period		3 years