Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accumulated depreciation, property and equipment	$ 6,003,357	$ 5,798,875
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Shares Issued	9,775,000	9,775,000
Preferred Stock, Shares Outstanding	9,775,000	9,775,000
Preferred Stock, Liquidation Preference, Value	$ 977,500	$ 977,500
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	337,559,718	333,771,660
Common stock, shares outstanding	337,559,718	333,771,660