Fair Value Measurements (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) property	Sep. 30, 2014 USD ($) property	Dec. 31, 2014 USD ($)
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	15.00%
Combined carrying value | $	$ 150,424	$ 133,543	$ 146,788
Vacant Owned Facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Number of vacant owned facilities	3	3
Number of vacant owned facilities sold	1	1
Number of vacant facilities reopened	1
Number of properties classified as fixed assets	1	2
Estimated combined fair value | $	$ 3,000	$ 3,000
Combined carrying value | $	$ 2,500	$ 2,700