Series D Preferred Shares - Additional Information (Detail) $ / shares in Units, $ in Thousands		3 Months Ended
	Dec. 07, 2016 USD ($) shares	Mar. 31, 2017 USD ($) $ / shares 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
Repurchase shares price | $		11,600
Warrants and investor SARs | $		$ 30,900	$ 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	3,536,000
Preferred shares with warrants					9,931,000
Shares repurchase and cancel, shares	464,000
Repurchase shares price | $	$ 11,600
Cumulative redeemable preferred shares, shares outstanding	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