Stock Based Compensation and Other Benefit Plans - Weighted-average Exercise Price and Weighted-Average Grant Date Fair Value, Options (Details) - $ / shares	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-average exercise price of the stock on the date of grant (in dollars per share)	$ 0.00	$ 4.32	$ 9.00
Weighted-average grant date fair value on the date of grant (in dollars per share)		$ 1.97	$ 3.91

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Period Type:	duration