Supplemental Financial Data (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Income Statement Elements [Abstract]
Litigation settlement/contingency expenses	$ 2,511	$ 5,110,000	$ 12,812,000
Insurance and bonds	$ 12,023	$ 12,514,000	$ 11,801,000