Stock-Based Compensation - Narrative (Details) (USD $)	12 Months Ended				1 Months Ended		12 Months Ended	1 Months Ended	12 Months Ended			1 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Stock options	Nov. 30, 2012 Stock options Independent directors	Aug. 31, 2011 Stock options Independent directors	Dec. 31, 2012 Stock options Independent directors	Mar. 31, 2010 Stock options Executive officer	Dec. 31, 2012 Restricted stock	Dec. 31, 2011 Restricted stock	Dec. 31, 2010 Restricted stock	Aug. 31, 2011 Restricted stock Executive officer	Nov. 30, 2010 Restricted stock Executive officer	Dec. 31, 2012 Minimum Stock options	Dec. 31, 2012 Maximum Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Approved and authorized maximum number of shares to be issued	3,000,000
Options, expiration period				10 years
Options, vesting period						6 months	6 months					5 years	3 years	3 years	5 years
Fair value of equity compensation grants awarded							$ 60,000
Grants awarded during period					9,160	10,000		3,539				360,417	61,177
Weighted average grant-date fair value of options granted					$ 6.55	$ 6.00		$ 17.68
Granted (in dollars per share)									$ 6.55	$ 6.00	$ 13.86	$ 6.00	$ 13.69
Compensation expense related to stock based awards outstanding	3,100,000	2,700,000	2,500,000
Forfeiture rate applied to options				5.50%
Proceeds received upon exercise of stock options	298,000	185,000	669,000
Exercise of stock options, shares	56,658	32,124	82,510
Total share-based compensation cost not yet recognized	5,400,000
Share-based compensation cost not yet recognized, period for recognition	3 years 10 months 24 days
Total intrinsic value of options exercised	130,000	143,000	799,000
Total fair value of shares vested	$ 1,997,000	$ 1,383,000	$ 2,518,000