Fair Value Measurements (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property	Dec. 31, 2013 USD ($) property
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	6 years
Average long-term sales growth forecast, over next 4 years, percent per year	13.00%
Combined carrying value	$ 150,600	$ 146,788
Vacant Owned Facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Number of vacant owned properties | property	3	4	6
Number properties classified as fixed assets | property	1	3	3
Number of vacant facilities owned, not exceeding carrying value | property			2
Estimated combined fair value	$ 3,100		$ 3,600
Combined carrying value	$ 2,500
Tangible asset impairment charges			100
Vacant Owned Facilities Classified in Fixed Assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Estimated combined fair value		$ 4,200
Combined carrying value		$ 3,900	$ 3,200