Stock-Based Compensation Stock-Based Compensation (Activity Pertaining to Nonemployee Director Stock Award Plan) (Details) (Directors Plan [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Directors Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Beginning Balance	192,500	199,500	178,500
Weighted average grant date price, beginning balance	$ 49.39	$ 48.37	$ 48.77
Number of Shares, Granted	0	0	31,500
Weighted average grant date price, granted	$ 0.00	$ 0.00	$ 53.81
Number of Shares, Exercised	(17,500)	(7,000)	(10,500)
Weighted Average Grant Date Price, Exercised	$ 32.53	$ 20.28	$ 21.96
Number of Shares, Forfeited	(3,500)	0	0
Weighted average grant date price, forfeited	$ 20.46	$ 0.00	$ 0.00
Number of Shares, Ending Balance	171,500	192,500	199,500
Weighted average grant date price, ending balance	$ 51.70	$ 49.39	$ 48.37