Stock-Based Compensation (Stock Appreciation Rights) (Details) (SARs, USD $)	9 Months Ended
	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Subject to SARs Outstanding & Exercisable	22,849
Weighted-Average Remaining Contractual Life	4 years 10 months 24 days
Exercise Price $23.26
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price (usd per share)	23.26
Number of Shares Subject to SARs Outstanding & Exercisable	2,000
Weighted-Average Remaining Contractual Life	4 years 9 months 18 days
Exercise Price $23.77
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price (usd per share)	23.77
Number of Shares Subject to SARs Outstanding & Exercisable	11,509
Weighted-Average Remaining Contractual Life	5 years 4 months 24 days
Exercise Price $29.25
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price (usd per share)	29.25
Number of Shares Subject to SARs Outstanding & Exercisable	9,340
Weighted-Average Remaining Contractual Life	4 years 4 months 24 days