Series D Preferred Shares - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended				9 Months Ended		0 Months Ended
	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2014 Adjusted	Dec. 31, 2012 ARS VI	Sep. 30, 2014 Series D Preferred Stock	Dec. 31, 2012 Series D Preferred Stock	Nov. 04, 2014 Series D Preferred Stock Subsequent Event	Dec. 31, 2012 Series D Preferred Stock ARS VI
Temporary Equity [Line Items]
Maximum period to issue and sell securities on private placement basis	2 years
Aggregate purchase price under Securities Purchase Agreement		$ 100,000		$ 100,000
Preferred shares total issued		4,000,000						4,000,000
Cumulative Redeemable Preferred Shares, par value								$ 0.01
Preferred shares with warrants						9,931,000
Stock Appreciation Rights	6,735,667.00	6,735,667.00	7,107,948.84
Stock Appreciation Rights Exercise Price					$ 6.00		$ 5.69
Fair value of Warrants and stock appreciation rights		$ 29,731
Warrants exercisable for common shares		9,931,000	10,479,889