Stock-Based Compensation (Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Number of Stock Options Outstanding
Outstanding, Options, Beginning Balance	153,418
Granted, Options	27,000	37,500	30,500
Exercised, Options	(16,361)	(45,154)	(78,035)
Cancelled, Options	(7,388)
Outstanding, Options, Ending Balance	156,669	153,418
Weighted Average Exercise Price
Weighted Average Exercise Price, Beginning Balance	$ 30.31
Granted, Weighted Average Exercise Price	$ 36.75
Exercised, Weighted Average Exercise Price	$ 27.72
Cancelled, Weighted Average Exercise Price	$ 29.74
Weighted Average Exercise Price, Ending Balance	$ 31.72	$ 30.31
Vested and Expected to Vest
Vested and expected to vest, Outstanding	149,084
Vested and expected to vest, Weighted Average Exercise Price	$ 31.91
Vested and Expected to Vest, Weighted Average Intrinsic Value	$ 5.60
Vested and expected to vest, Aggregate Intrinsic Value	$ 1,206
Exercisable, Outstanding	63,090
Exercisable, Weighted Average Exercise Price	$ 30.28
Exercisable, Weighted Average Intrinsic Value	$ 5.38
Exercisable, Aggregate Intrinsic Value	613
Additional Disclosures
Outstanding, Weighted Average Intrinsic Value	$ 5.56
Outstanding, Options, Aggregate Intrinsic Value	$ 1,296
Minimum [Member]
Weighted Average Exercise Price
Weighted Average Exercise Price, Beginning Balance	$ 18.37
Granted, Weighted Average Exercise Price	$ 35.46
Exercised, Weighted Average Exercise Price	$ 18.37
Cancelled, Weighted Average Exercise Price	$ 26.99
Weighted Average Exercise Price, Ending Balance	$ 21.82
Vested and Expected to Vest
Vested and expected to vest, Weighted Average Exercise Price	$ 21.82
Exercisable, Weighted Average Exercise Price	$ 21.82
Maximum [Member]
Weighted Average Exercise Price
Weighted Average Exercise Price, Beginning Balance	$ 37.60
Granted, Weighted Average Exercise Price	$ 40.62
Exercised, Weighted Average Exercise Price	$ 37.60
Cancelled, Weighted Average Exercise Price	$ 36.75
Weighted Average Exercise Price, Ending Balance	$ 40.62
Vested and Expected to Vest
Vested and expected to vest, Weighted Average Exercise Price	$ 40.62
Exercisable, Weighted Average Exercise Price	$ 37.60