Quarterly Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

Quarterly Financial Information Disclosure [Abstract]

Summary of Quarterly Data

	2016
	1st			2nd			3rd			4th			Year
Total revenue	$	10.0		$	9.1		$	10.4		$	12.6		$	42.1
Gross margin	$	6.8		$	5.9		$	7.0		$	8.6		$	28.3
Operating loss	$	(5.6	)	$	(6.0	)	$	(5.0	)	$	(2.2	)	$	(18.8	)
Loss before income taxes	$	(5.8	)	$	(6.2	)	$	(5.8	)	$	(3.1	)	$	(20.9	)
Net loss available to common stockholders	$	(6.0	)	$	(6.3	)	$	(6.0	)	$	(3.3	)	$	(21.6	)
Per share of common stock:
Basic net loss available to common stockholders	$	(0.24	)	$	(0.25	)	$	(0.24	)	$	(0.13	)	$	(0.86	)
Diluted net loss available to common stockholders	$	(0.24	)	$	(0.25	)	$	(0.24	)	$	(0.13	)	$	(0.86	)

	2015
	1st			2nd			3rd			4th			Year
Total revenue	$	9.3		$	9.7		$	10.5		$	10.4		$	39.9
Gross margin	$	6.7		$	7.0		$	8.0		$	7.5		$	29.2
Operating loss	$	(3.7	)	$	(3.4	)	$	(3.8	)	$	(4.2	)	$	(15.1	)
Loss before income taxes	$	(3.8	)	$	(3.6	)	$	(3.9	)	$	(4.3	)	$	(15.6	)
Net loss available to common stockholders	$	(4.0	)	$	(3.7	)	$	(4.1	)	$	(4.5	)	$	(16.3	)
Per share of common stock:
Basic net loss available to common stockholders	$	(0.18	)	$	(0.17	)	$	(0.17	)	$	(0.18	)	$	(0.70	)
Diluted net loss available to common stockholders	$	(0.18	)	$	(0.17	)	$	(0.17	)	$	(0.18	)	$	(0.70	)