Redeemable Preferred Stock (Details)		3 Months Ended	12 Months Ended						30 Months Ended
	Jun. 14, 2013 USD ($) shares	Jun. 30, 2006 USD ($)	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) shares	Dec. 31, 1998 shares	Dec. 31, 1991 shares	Dec. 31, 1990 Tranche $ / shares shares	Jun. 30, 1995 USD ($)	Jun. 11, 2013 USD ($)	Mar. 15, 2011 shares
Class of Stock [Line Items]
Preferred stock dividend rate per annum			12.00%	12.00%
Dividends Payable			$ 3,889,000	$ 3,890,000	$ 3,926,000
Senior Redeemable Preferred Stock [Abstract]
Redeemable preferred stock liquidation value (in dollar per share) | $ / shares				$ 1,000
Maximum redemption of redeemable preferred stock										$ 2,000,000
Minimum percentage of discount on redemption of redeemable preferred stock										10.00%
Redemption amount of senior redeemable preferred stock	$ 2,000,000
Percentage of discount on redemption of redeemable preferred stock	10.00%
Common stock held by related parties			39.30%
12% Cumulative Exchangeable Redeemable Preferred Stock [Abstract]
Number of shares declared as dividend (in shares) | shares							736,863	736,863
Number of annual tranches during the period | Tranche								5
Accrued paid-in cash dividends									$ 15,100,000
Senior Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock dividend rate per annum			14.125%	14.125%
Senior Redeemable Preferred Stock [Abstract]
Percentage of redeemable preferred stock redeemed	54.50%
Senior redeemable preferred stock maturity date				Feb. 28, 2018
Carrying value of senior redeemable preferred stock	$ 2,200,000
Gain on redemption of senior preferred stock	$ 200,000
Undeclared unpaid dividends				$ 1,600,000	1,500,000
Accrued dividends reported as interest expenses			$ 67,000	$ 67,000	103,000
Senior Redeemable Preferred Stock [Member] | Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Percentage of redeemable preferred stock held by related party after redemption				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				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				82.70%
Public Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock authorized (in shares) | shares								6,000,000
Preferred stock par value (in dollar per share) | $ / shares								$ 0.01
Preferred stock dividend rate per annum			12.00%	12.00%			6.00%	6.00%
Dividends Payable				$ 92,100,000	88,200,000
Principal and accrued dividends of redeemable preferred stock				$ 123,900,000	$ 120,100,000
Preferred stock issued and outstanding (in shares) | 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
Period during which redeemable preferred stock not callable				12 months
Preferred stock dividend rate per annum (in dollars per share) | $ / shares			$ 0.60	$ 1.20
Preferred stock, liquidation preference (in dollars per share) | $ / shares				$ 10
Dividends on preferred stock			$ 3,800,000	$ 3,800,000	$ 3,800,000
Accrued paid-in kind dividends									4,000,000
Redemption of public preferred stock (in shares) | 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
Series A-1 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock authorized (in shares) | shares				1,250
Preferred stock par value (in dollar per share) | $ / shares				$ 0.01
Series A-1 Preferred Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Related party preferred stock held after redemption (in shares) | shares	163
Series A-1 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock issued and outstanding (in shares) | shares	197			197	197
Series A-1 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member] | Porter [Member]
Senior Redeemable Preferred Stock [Abstract]
Number of redeemable preferred stock acquired by beneficial owner (in shares) | shares											75
Series A-1 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Related party preferred stock held after redemption (in shares) | shares				163
Series A-2 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock authorized (in shares) | shares				1,750
Preferred stock par value (in dollar per share) | $ / shares				$ 0.01
Series A-2 Preferred Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Related party preferred stock held after redemption (in shares) | shares	228
Series A-2 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock issued and outstanding (in shares) | shares	276			276
Series A-2 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member] | Porter [Member]
Senior Redeemable Preferred Stock [Abstract]
Number of redeemable preferred stock acquired by beneficial owner (in shares) | shares											105
Series A-2 Preferred Stock [Member] | Senior Redeemable Preferred Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Related party preferred stock held after redemption (in shares) | shares			228
Class A Common Stock [Member] | Porter [Member]
Senior Redeemable Preferred Stock [Abstract]
Common stock held by related parties				39.30%
Class A Common Stock [Member] | Porter And Toxford [Member]
Senior Redeemable Preferred Stock [Abstract]
Common stock held by related parties	39.30%