Warrants, Restricted Stock, Restricted Stock Units, Options and Option Matching Rights - Schedule of Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning balance (shares)	33,600	56,600	156,200
Exercised (shares)	(2,000)	(18,000)	(81,600)
Forfeited (shares)	(18,300)	(5,000)	(18,000)
Options outstanding, ending balance (shares)	13,300	33,600	56,600	156,200
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning balance (usd per share)	$ 68.92	$ 48.50	$ 33.25
Options outstanding, ending balance (usd per share)	$ 26.03	$ 68.92	$ 48.50	$ 33.25
Options outstanding, weighted average remaining contractual life (in years)	8 months 27 days	1 year 1 month 10 days	2 years 7 months 10 days	1 year 5 months 19 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning balance (usd per share)	$ 7.95	$ 7.95	$ 7.95
Exercised (usd per share)		7.95	13.95
Forfeited (usd per share)	14.85	14.85
Canceled (usd per share)			13.95
Options outstanding, ending balance (usd per share)	15.00	7.95	7.95	$ 7.95
Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning balance (usd per share)	131.10	131.10	131.10
Exercised (usd per share)		9.90	27.15
Forfeited (usd per share)	131.10	82.95
Canceled (usd per share)			127.95
Options outstanding, ending balance (usd per share)	$ 40.05	$ 131.10	$ 131.10	$ 131.10