Shareholders' Deficit (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 14, 2014	Jul. 22, 2011
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock, shares authorized	95,000,000	95,000,000		95,000,000
Previous maximum ownership percentage				19.99%
Preferred stock authorized shares	5,000,000	5,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common shares	32,473,000	32,141,000	30,667,000
Ending balance, common shares	32,733,000	32,473,000	32,141,000
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Debt conversion, shares issued (in shares)	0	0	995,000
Issuance of equity awards, net	260,000	332,000	479,000
Series A Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Preferred stock authorized shares					1
Liquidation value per share					$ 1
Shares issued					1