Subsequent Events - Narrative (Details) - USD ($)	1 Months Ended	6 Months Ended
	Jul. 31, 2018	Jun. 30, 2018	Aug. 09, 2018	Jul. 21, 2018	Dec. 31, 2017
Common Stock
Subsequent Event [Line Items]
Preferred stock conversion (in shares)		1,851,000
Series C Preferred Stock
Subsequent Event [Line Items]
Preferred stock, shares issued (in shares)		1,275			0
Series C Preferred Stock | Preferred Stock
Subsequent Event [Line Items]
Preferred stock conversion (in shares)		(475)
Series C Preferred Stock | Common Stock
Subsequent Event [Line Items]
Preferred stock conversion (in shares)		1,583,000
Subsequent Event
Subsequent Event [Line Items]
Stock repurchase program, authorized amount (up to)				$ 750,000
Subsequent Event | Series C Preferred Stock
Subsequent Event [Line Items]
Preferred stock, shares issued (in shares)			775
Subsequent Event | Series C Preferred Stock | Preferred Stock
Subsequent Event [Line Items]
Preferred stock conversion (in shares)	500
Subsequent Event | Series C Preferred Stock | Common Stock
Subsequent Event [Line Items]
Preferred stock conversion (in shares)	1,666,666