Investment in Unconsolidated Entity - Narrative (Details)		3 Months Ended		9 Months Ended
	Aug. 15, 2017 USD ($) officer board_seat $ / shares shares	Sep. 30, 2017 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) $ / shares
Business Acquisition [Line Items]
Equity Interest Issuable in Acquisition, Value Assigned				$ 198,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01		$ 0.01		$ 0.01
Investment in unconsolidated entity		$ 15,771,000		$ 15,771,000		$ 0
Equity in income of unconsolidated entity		968,000	$ 0	968,000	$ 0
Challenger Subsidiary [Member]
Business Acquisition [Line Items]
Ownership percent	49.90%
Ownership percent, outside party	50.10%
Common stock issued in connection with the investment in the Challenger Subsidiary (shares) | shares	1,497,000
Equity Interest Issuable in Acquisition, Value Assigned	$ 200,000
Optional additional voting interest could be acquired	20.10%
Acquisition related costs	$ 241,000
Goodwill	5,100,000
Investment in unconsolidated entity	$ 15,100,000
Board seats held | board_seat	2
Board seats available | board_seat	5
Number of officers | officer	6
Impairment loss		$ 0		$ 0
Common Stock | Challenger Subsidiary [Member]
Business Acquisition [Line Items]
Common stock issued in connection with the investment in the Challenger Subsidiary (shares) | shares	1,477,000
Holdback Shares | Challenger Subsidiary [Member]
Business Acquisition [Line Items]
Common stock issued in connection with the investment in the Challenger Subsidiary (shares) | shares	20,000