Property and Equipment (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Unfunded construction and equipment purchases	$ 18.3
Depreciation expense	$ 35.4	$ 33.2	$ 29.8
Building and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	20 years
Building and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	40 years
Movable Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years
Movable Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years