Fair Value Measurements (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) property	Mar. 31, 2015 USD ($) property	Dec. 31, 2015 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	6 years
Average long-term sales growth forecast, over next 4 years, percent per year	15.00%
Combined carrying value	$ 150,378	$ 149,087	$ 150,600
Vacant Owned Facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Number of vacant owned facilities | property	1	3
Number of properties classified as fixed assets | property	1	3
Estimated combined fair value	$ 5,300	$ 4,100
Combined carrying value	$ 2,500	$ 3,900