Fair Value Measurements (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Percentage of deferred compensation invested in life insurance contracts	65.00%
Number of years long-term sales growth forecasted over	3 years
Average long-term sales growth forecast, over next 4 years, percent per year	20.00%
Fixed assets, net	$ 129,060	$ 125,982	$ 112,783
Vacant Owned Facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Number Of Vacant Owned Facilities	3
Number Of Vacant Owned Facilities Sold	1
Number Of Properties Classified As Fixed Assets	2		4
Estimated combined fair value	3,100		14,200
Fixed assets, net	$ 2,700		$ 5,200
Number Of Vacant Facilities Owned Not Exceeding Carrying Value			4