Redeemable Preferred Stock (Details)	1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended				30 Months Ended
	Dec. 31, 2009 Tranche	Sep. 30, 2015 USD ($) $ / shares shares	Sep. 30, 2014 USD ($)	Jun. 30, 2006 USD ($)	Sep. 30, 2015 USD ($) $ / shares shares	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) shares	Dec. 31, 1998 shares	Dec. 31, 1991 $ / shares shares	Dec. 31, 1990 $ / shares shares	Jun. 30, 1995 USD ($)
Senior Redeemable Preferred Stock [Abstract]
Redeemable preferred stock liquidation value (in dollar per share) | $ / shares		$ 1,000			$ 1,000
Percentage of redeemable preferred stock held by related party after redemption (in hundredths)		39.30%			39.30%
12% Cumulative Exchangeable Redeemable Preferred Stock [Abstract]
Number of annual tranches during the period | Tranche	5
Accrued paid-in kind dividends | $											$ 4,000,000
Accrued paid-in cash dividends | $											15,100,000
Redemption of public preferred stock (in shares)								410,000
Reduced amount of Paid in kind dividends due to redemption of public preferred stock | $											3,500,000
Adjusted amount of accrued cash dividends due to redemption of public preferred stock | $											9,900,000
Revised accrued dividends to reflect change from Pik dividends to cash dividends | $											$ 13,400,000
Senior Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock dividend rate per annum (in hundredths)					14.125%
Senior Redeemable Preferred Stock [Abstract]
Undeclared unpaid dividends | $		$ 1,500,000			$ 1,500,000		$ 1,500,000
Accrued dividends reported as interest expenses | $		$ 17,000	$ 17,000		$ 50,000	$ 50,000
Senior Redeemable Preferred Stock [Member] | Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Senior redeemable preferred stock maturity date					Feb. 28, 2017
Percentage of redeemable preferred stock held by related party after redemption (in hundredths)		76.40%			76.40%
Senior Redeemable Preferred Stock [Member] | Porter [Member]
Senior Redeemable Preferred Stock [Abstract]
Percentage of redeemable preferred stock held by related party after redemption (in hundredths)		6.30%			6.30%
Senior Redeemable Preferred Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Percentage of redeemable preferred stock held by related party after redemption (in hundredths)		82.70%			82.70%
Public Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock authorized (in shares)		6,000,000			6,000,000
Preferred stock par value (in dollar per share) | $ / shares		$ 0.01			$ 0.01
Preferred stock dividend rate per annum (in hundredths)					12.00%		12.00%		6.00%	6.00%
Dividends Payable | $		$ 91,100,000			$ 91,100,000		$ 88,200,000
Carrying value of redeemable preferred stock | $		$ 123,000,000			$ 123,000,000		$ 120,100,000
Preferred stock issued and outstanding (in shares)		3,185,586			3,185,586					2,858,723
12% Cumulative Exchangeable Redeemable Preferred Stock [Abstract]
Adjusted accrued accretion of public preferred stock | $				$ 1,500,000
Number of shares declared as dividend (in shares)									736,863	736,863
Period during which redeemable preferred stock not callable					12 months
Preferred stock dividend rate per annum (in dollars per share) | $ / shares					$ 1.20				$ 0.60	$ 0.60
Preferred stock, liquidation preference (in dollars per share) | $ / shares		$ 10			$ 10
Dividends on preferred stock | $		$ 1,000,000	$ 1,000,000		$ 2,900,000	$ 2,900,000
Series A-1 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock authorized (in shares)		1,250			1,250
Preferred stock par value (in dollar per share) | $ / shares		$ 0.01			$ 0.01
Preferred stock issued and outstanding (in shares)							197
Senior Redeemable Preferred Stock [Abstract]
Related party preferred stock held after redemption (in shares)		163			163
Series A-1 Preferred Stock [Member] | Public Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock issued and outstanding (in shares)							3,185,586
Series A-2 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock authorized (in shares)		1,750			1,750
Preferred stock par value (in dollar per share) | $ / shares		$ 0.01			$ 0.01
Preferred stock issued and outstanding (in shares)		276			276		276
Senior Redeemable Preferred Stock [Abstract]
Related party preferred stock held after redemption (in shares)		228			228
Series A-2 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock issued and outstanding (in shares)		197			197
Class A Common Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Common stock held by related parties (in hundredths)		39.30%			39.30%