Significant Accounting Policies (Details 7) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Significant Accounting Policies
Interest expense	$ (229,654)	$ (249,780)	$ (692,801)	$ (758,945)
Other Income	72,545	54,987	260,736	139,918
Net income attributable to noncontrolling interests	(71,653)	(44,161)	(244,868)	(172,828)
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS	$ 420,009	$ 251,968	1,432,086	1,000,203
Accumulated Net Gain (Loss) from Derivatives Including Portion Attributable to Noncontrolling Interest | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Interest expense			(8,097)	(7,947)
Accumulated Net Gain (Loss) from Derivatives Attributable to Noncontrolling Interest | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Net income attributable to noncontrolling interests			1,161	1,155
Accumulated derivative losses, net | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS			(6,936)	$ (6,792)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Other Income			80,187
Accumulated Net Investment Gain (Loss) Attributable to Noncontrolling Interest | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
Net income attributable to noncontrolling interests			(11,502)
Net gains (losses) on marketable securities | Amount reclassified from accumulated other comprehensive income (loss)
Significant Accounting Policies
NET INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS			$ 68,685