Discontinued Operations - Option Agreement Net Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Revenues	$ 0	$ 0	$ 14,967,000
Operating income (loss)	0	0	(875,000)
Gain on disposal	0	0	5,007,000
Interest expense	0	0	(4,000)
Income tax provision	0	0	(110,000)
Net income from discontinued operations	$ 0	$ 0	$ 4,018,000