Stock-Based Compensation (Restricted Stock Unit Activity) (Details) (Restricted Stock Units R S U [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted Stock Units R S U [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units Outstanding at beginning of year	772,322	710,591	596,648
Units granted	190,846	178,144	200,819
Shares issued	(127,087)	(108,170)	(82,982)
Units forfeited	(69,386)	(8,243)	(3,894)
Units Outstanding at end of year	766,695	772,322	710,591
Units vested at end of year	311,546	303,781	244,897
Outstanding at beginning of year, Weighted Average Fair Value at Date of Grant	$ 32.57	$ 29.53	$ 25.78
Units granted, Weighted Average Fair Value at Date of Grant	$ 49.82	$ 43.36	$ 40.15
Shares Issued, Weighted Average Fair Value at Date of Grant	$ 34.48	$ 29.74	$ 28.10
Units forfeited, Weighted Average Fair Value at Date of Grant	$ 37.91	$ 41.22	$ 34.44
Outstanding at end of year, Weighted Average Fair Value at Date of Grant	$ 36.06	$ 32.57	$ 29.53
Units vested at end of year, Weighted Average Fair Value at Date of Grant	$ 24.98	$ 24.85	$ 24.03