Equity Compensation, Employment Agreements and Other Benefit Plans (Details) (USD $)	0 Months Ended	3 Months Ended		6 Months Ended
	Aug. 01, 2013	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Share based compensation
Maximum shares authorized for grant		13,500,000		13,500,000
Shares available for grant		9,500,000		9,500,000
Dividends Declared per Share of Common Stock, special dividend (in dollars per share)	$ 0.28			$ 0.50
Accrued Dividends Payable		$ 80,440,000	$ 83,263,000	$ 80,440,000	$ 83,263,000	$ 72,222,000
Expense Recognized for Equity-Based Compensation Instruments		1,301,000	1,480,000	2,186,000	2,581,000
DER
Share based compensation
Payments attributable to DERs		922,000	378,000	1,200,000	825,000
Awards Outstanding (in shares)		1,316,222		1,316,222
DERs outstanding that are attached to common stock options (in shares)		403,250		403,250
DERS outstanding that are awarded in connection with or attached to RSU (in shares)		912,972		912,972
Average forfeiture rate on DERs outstanding attached to RSUs (as a percent)				17.10%
Average forfeiture rate on DERs outstanding, other than attached to RSUs				0.00%
Weighted average period over which DERs are scheduled to elapse				1 year 7 months 6 days
Expense Recognized for Equity-Based Compensation Instruments		51,000	59,000	102,000	118,000
Stock options
Share based compensation
Period to determine market value of the common stock to qualify as an incentive stock option for tax purposes				1 year
Maximum grant date market value of the common stock to be received upon exercise of options in one calendar year				100,000
Exercise price of an ISO relative to fair market value on the grant date, minimum (as a percent)				100.00%
Exercise price of an ISO granted to a 10% stockholder relative to fair market value on the grant date, minimum (as a percent)				110.00%
Percentage of stockholders to whom 110% of ISO is granted				10.00%
Maximum period for exercise of stock options				10 years
Stock options exercised (in shares)				20,000	0
Stock options cancelled (in shares)				0	50,000
Stock options, outstanding (in shares)		407,000		407,000
Options exercisable at end of year (in dollars per share)		$ 10.23		$ 10.23
Aggregate intrinsic value of total stock options Outstanding		250		250
Restricted Stock
Share based compensation
Granted (in shares)		16,412	66,558	28,743	81,439
Unrecognized compensation cost		2,900,000		2,900,000		3,700,000
Accrued Dividends Payable		444,000		444,000		428,000
Period for recognizing unrecognized compensation cost				1 year 3 months 18 days
Expense Recognized for Equity-Based Compensation Instruments		591,000	1,155,000	1,135,000	1,917,000
Restricted Stock Units
Share based compensation
Granted (in shares)		40,324	0	40,324	0
Unrecognized compensation cost		1,900,000		1,900,000		2,600,000
Period for recognizing unrecognized compensation cost				1 year 10 months 24 days
Weighted average forfeiture rate of unvested RSUs (as a percent)				17.10%
Expense Recognized for Equity-Based Compensation Instruments		$ 659,000	$ 266,000	$ 949,000	$ 546,000
2010 Equity Compensation Plan
Share based compensation
Maximum number of common shares that can be granted to participant in any one year				1,500,000
Period during which a participant can be awarded the maximum number of shares allowable under the Plan				1 year
Maximum percentage of common shares that can be owned or deemed to be owned by a participant				9.80%