Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accumulated depreciation, property and equipment	$ 7,036,587	$ 6,613,219
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	0	0
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Liquidation Preference, Value	$ 0	$ 0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares outstanding	366,115,800	360,536,659