Stock-Based Compensation (Details 1) (Stock Options [Member], USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Stock Options [Member]
Balance, beginning (in shares)	30,628
Exercised, (in shares)	13,192
Balance, ending (in shares)	17,436
Exercisable, (in shares)	17,436
Outstanding, weighted average exercise price	$ 17.79
Exercised, weighted average exercise price	$ 16.47
Outstanding, weighted average exercise price	$ 18.79
Exercisable, weighted average exercise price	$ 18.79
Outstanding, average remaining contractual term years, beginning	10 months 2 days
Outstanding, average remaining contractual term years, ending	3 months 4 days
Exercisable, average remaining contractual term years	3 months 4 days
Outstanding, aggregate intrinsic value	$ 545
Outstanding, aggregate intrinsic value	404
Exercisable, aggregate intrinsic value	$ 404