Subsequent events (Details) $ / shares in Units, $ in Millions				2 Months Ended	3 Months Ended	6 Months Ended	17 Months Ended
	Apr. 26, 2016 USD ($)	Apr. 15, 2016 USD ($) $ / shares item shares	Apr. 12, 2016 USD ($) $ / shares shares	Mar. 09, 2016 shares	Mar. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 09, 2016 shares	Apr. 11, 2016 shares
Subsequent events
Common stock repurchased (in shares)				1,300,000			4,900,000
Certain officers
Subsequent events
Restricted stock awards expensed | $					$ 0.5
Modified "Dutch auction" tender offer
Subsequent events
Common stock repurchased (in shares)			3,900,000
Restricted shares repurchase price | $ / shares			$ 3.60
Subsequent event
Subsequent events
Number of Series A Preferred Stock converted								708,352
Number of common stock that Series A Preferred Stock converted into								2,162,907
Conversion ratio of common stock per share of Series A Preferred Stock								3.05
Subsequent event | Certain officers
Subsequent events
Restricted stock awards granted (in shares)		450,000
Minimum volume weighted average price on NASDAQ (per share) | $ / shares		3.50
Number of consecutive trading days equal or over $3.50 per share | item		7
Number of trading days equal or over $3.50 per share over a consecutive thirty-five day period | item		10
Number of consecutive days which any ten trading days equal or over $3.50 per share | item		35
Value at market condition | $		$ 0.7
Subsequent event | Modified "Dutch auction" tender offer
Subsequent events
Credit Facility borrowed | $			$ 13.9
Common stock repurchased (in shares)			3,900,000
Credit Facility repaid | $	$ 4.0
Repayments of Lines of Credit | $	$ 4.0
Subsequent event | Scenario, Forecast [Member] | Certain officers
Subsequent events
Restricted stock awards expensed | $						$ 0.2