Stock-Based Compensation (Details) (2007 Incentive Stock Plan [Member], Restricted Stock [Member])	3 Months Ended
	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Balance, January 1 (in shares)	961,440
Granted (in shares)	315,088
Forfeited (in shares)	(8,944)
Reduced for income tax obligations (in shares)	(1,716)
Balance at end of period (in shares)	1,265,868
Vested (in shares)	737,320
Non-vested (in shares)	528,548
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Balance, January 1 (in shares)	503,440
Granted (in shares)	153,088
Forfeited (in shares)	(8,944)
Reduced for income tax obligations (in shares)	(1,716)
Balance at end of period (in shares)	645,868
Vested (in shares)	288,320
Non-vested (in shares)	357,548
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Balance, January 1 (in shares)	458,000
Granted (in shares)	162,000
Forfeited (in shares)	0
Reduced for income tax obligations (in shares)	0
Balance at end of period (in shares)	620,000
Vested (in shares)	449,000
Non-vested (in shares)	171,000