CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 3,258,000	$ 2,927,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	62,307,024	63,324,409
Common stock, shares outstanding	62,307,024	63,324,409
Series B Preferred Stock [Member]
Preferred Stock, par or value	$ 0.001	$ 0.001
Preferred Stock, liquidation preference per share	$ 0.001	$ 0.001
Preferred Stock, shares authorized	40,000,000	40,000,000
Preferred Stock, shares issued	25,044,939	25,117,000
Preferred Stock, shares outstanding	25,044,939	25,117,000
Series J Preferred Stock [Member]
Preferred Stock, par or value	$ 0	$ 0
Preferred Stock, liquidation preference	192,500,000	192,500,000
Preferred Stock, shares authorized	7,700,000	7,700,000
Preferred Stock, shares issued	7,700,000	7,700,000
Preferred Stock, shares outstanding	7,700,000	7,700,000
Series K Preferred Stock [Member]
Preferred Stock, par or value	$ 0	$ 0
Preferred Stock, liquidation preference	$ 170,000,000	$ 170,000,000
Preferred Stock, shares authorized	6,800,000	6,800,000
Preferred Stock, shares issued	6,800,000	6,800,000
Preferred Stock, shares outstanding	6,800,000	6,800,000