10 3/4% Series B Cumulative Exchangeable Redeemable Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands										3 Months Ended		9 Months Ended		12 Months Ended	61 Months Ended
	Jul. 09, 2019	Apr. 27, 2018	Nov. 02, 2017	Oct. 15, 2013	Oct. 15, 2011	Oct. 15, 2010	Oct. 15, 2009	Apr. 05, 2004	Oct. 30, 2003	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Oct. 30, 2008	Feb. 18, 2004
Class Of Stock [Line Items]
Series B preferred stock adjustment to contract settlement value at reporting date classified as interest expense										$ 2,400	$ 2,400	$ 7,300	$ 7,300
Series B Preferred Stock Litigation
Class Of Stock [Line Items]
Claiming percentage of litigation			94.16%
Series A Preferred Stock
Class Of Stock [Line Items]
Preferred stock par value per share									$ 0.01
Liquidation preference per share									$ 1,000
Gross proceeds from the issuance of Series A preferred Stock									$ 75,000
Series A Preferred Stock | Private Placement
Class Of Stock [Line Items]
Preferred stock, shares issued									75,000
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares issued										90,549		90,549		90,549
Preferred stock par value per share																$ 0.01
Liquidation preference per share										$ 1,000		$ 1,000		$ 1,000		$ 1,000
Shares of Series B preferred stock exchanged for Series A preferred stock								76,702
Purchase price percentage as of aggregate liquidation preference												101.00%
Rate of redemption of Preferred stock for cash					100.00%	101.792%	103.583%
Rate of redemption of Preferred stock at purchase price												100.00%
Dividends on the Series B preferred stock												10.75%		10.75%
Increase in carrying value of preferred stock															$ 17,300
Stock requested to be repurchased				92,223
Purchase price of stock requested to be repurchased				$ 126,900
Stock repurchased				1,800
Purchase price of stock repurchased				$ 2,500
Offer price in cash as percentage of liquidation preference												101.00%
Aggregate cumulative unpaid dividends on outstanding shares										$ 92,067		$ 92,067		$ 84,766
Series B Preferred Stock | Minimum
Class Of Stock [Line Items]
Percentage of ownership on outstanding equity to be held by foreign entities		25.00%
Series B Preferred Stock | Maximum
Class Of Stock [Line Items]
Percentage of ownership on outstanding equity to be held by foreign entities	25.00%