CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts	$ 6,671,000	$ 4,311,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	60,685,420	60,430,613
Common stock, shares outstanding	60,685,420	60,430,613
Series B Preferred Stock [Member]
Preferred Stock, par 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	24,954,059	25,029,059
Preferred Stock, shares outstanding	24,954,059	25,029,059
Series J Preferred Stock [Member]
Preferred Stock, par 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 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