Stock Compensation Summary of stock option activity for the period (Details) (USD $)	9 Months Ended
	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at January 1, 2012 (in shares)	1,997,778
Outstanding at January 1, 2012 Average Price (in dollars per share)	$ 11.33
Options Granted (in shares)	323,950
Options Granted, Average Exercise Price (in dollars per share)	$ 12.96
Options Exercised, Shares (in shares)	(281,324)
Options Exercised, Average Exercise Price (in dollars per share)	$ 11.07
Cancelled or Forfeited (in shares)	(25,199)
Cancelled or Forfeited, Average Exercise Price (in dollars per share)	$ 11.05
Outstanding at June 30, 2012 (in shares)	2,015,205
Outstanding at June 30, 2012 Average Price (in dollars per share)	$ 11.61
Outstanding at June 30, 2012 Weighted Average Life (in years)	6 years 7 months 1 day
Exercisable at June 30, 2012 (in shares)	1,363,466
Exercisable at June 30, 2012, Average Exercise Price (in dollars per share)	$ 11.62