Series D Preferred Shares - Additional Information (Detail) $ / shares in Units, $ in Thousands	Jun. 22, 2017 USD ($) shares	Dec. 07, 2016 USD ($) shares	Jun. 30, 2017 USD ($) $ / shares	Mar. 31, 2017 shares	Dec. 31, 2016 USD ($)	Sep. 30, 2015 USD ($) Covenant	Oct. 01, 2012 USD ($) $ / shares shares
Temporary Equity [Line Items]
Aggregate purchase price under Securities Purchase Agreement | $			$ 100,000
Stock Appreciation Rights							6,735,667
Warrants and investor SARs | $			$ 27,500		$ 30,400
Adjusted
Temporary Equity [Line Items]
Warrants exercisable for common shares				11,035,875
Stock Appreciation Rights				7,485,045
ARS VI
Temporary Equity [Line Items]
Aggregate purchase price under Securities Purchase Agreement | $							$ 100,000
Preferred Series D
Temporary Equity [Line Items]
Cumulative redeemable preferred shares, shares issued	3,133,720	3,536,000
Preferred shares with warrants							9,931,000
Shares repurchase and cancel, shares	402,280	464,000
Repurchase shares price | $	$ 10,057	$ 11,600
Cumulative redeemable preferred shares, shares outstanding	3,133,720	3,536,000
Warrants Exercise Price | $ / shares							$ 6.00
Preferred Series D | Adjusted
Temporary Equity [Line Items]
Warrants Exercise Price | $ / shares			$ 5.40
Preferred Series D | ARS VI
Temporary Equity [Line Items]
Cumulative redeemable preferred shares, shares issued							4,000,000
Cumulative Redeemable Preferred Shares, par value | $ / shares							$ 0.01
Number of covenants | Covenant						2
Consideration paid under Securities Purchase Agreement | $						$ 450