Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended			3 Months Ended	12 Months Ended			0 Months Ended				12 Months Ended
	Feb. 27, 2008 Long-term incentive plan	Dec. 31, 2012 Long-term incentive plan	Feb. 26, 2008 Long-term incentive plan	Sep. 30, 2010 Stock options	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2010 Stock options	Apr. 25, 2012 Vested stock grants Directors Long-term incentive plan	Apr. 29, 2011 Vested stock grants Directors Long-term incentive plan	Sep. 22, 2010 Vested stock grants Directors Long-term incentive plan	Apr. 28, 2010 Vested stock grants Directors Long-term incentive plan	Dec. 31, 2012 Vested stock grants Directors Long-term incentive plan	Dec. 31, 2011 Vested stock grants Directors Long-term incentive plan	Dec. 31, 2010 Vested stock grants Directors Long-term incentive plan
Stock-Based Compensation
Maximum number of shares of common stock available for awards	2,175,000		2,000,000
Term of plan	20 years
Shares remaining available for awards		0
Historical volatility period of common stock used to estimate the fair value of each option grant					90 days
Number of shares expired				9,534
Weighted average exercise price of shares expired (in dollars per share)				$ 17.03
Vested stock grants to directors (in shares)								12,995	14,009	1,504	12,892
Value of vested stock grants to directors (in shares)								$ 245	$ 245	$ 25	$ 220
Recognized stock-based compensation expense					0	0	0					245	245	245
Unrecognized compensation costs related to unvested options					0
Number of shares
Outstanding at the beginning of the period (in shares)					88,124	156,446	551,007
Granted (in shares)					0	0	0
Exercised (in shares)					(81,023)	(68,322)	(385,027)
Forfeited (in shares)							(9,534)
Expired (in shares)				(9,534)
Outstanding at the end of the period (in shares)					7,101	88,124	156,446
Vested and Exercisable at the end of the period (in shares)					7,101
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)					$ 6.44	$ 5.01	$ 4.50
Exercised (in dollars per share)					$ 6.49	$ 3.17	$ 4.60
Forfeited (in dollars per share)							$ 17.03
Expired (in dollars per share)				$ 17.03
Outstanding at the end of the period (in dollars per share)					$ 5.75	$ 6.44	$ 5.01
Vested and Exercisable at the end of the period					$ 5.75
Weighted Average Remaining Contractual Term
Outstanding at the end of the period					1 year 4 months 24 days
Vested and Exercisable at the end of the period					1 year 4 months 24 days
Aggregate Intrinsic Value
Outstanding at the end of the period					115
Vested and Exercisable at the end of the period					115
Intrinsic value of options exercised					$ 1,025	$ 994	$ 4,630
Nonvested options outstanding (in shares)					0	0	0