Equity (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (9,237)	$ (50,261)	$ (5,275)	$ (35,366)
Other comprehensive (loss) income before reclassifications	(9,956)	10,289	(15,933)	(6,038)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,365	1,440	4,525	2,634
Net current-period Other comprehensive income (loss)	(7,591)	11,729	(11,408)	(3,404)
Net current-period Other comprehensive (income) loss attributable to noncontrolling interests	(67)	(257)	(212)	(19)
Ending balance	(16,895)	(38,789)	(16,895)	(38,789)
Interest Expense
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,572	2,046	4,619	3,947
Other income and (expense)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(207)	(606)	(94)	(1,313)
Unrealized Gains (Losses) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(28,179)	(15,690)	(25,579)	(25,888)
Other comprehensive (loss) income before reclassifications	(3,937)	1,654	(8,548)	10,778
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,365	1,440	4,525	2,634
Net current-period Other comprehensive income (loss)	(1,572)	3,094	(4,023)	13,412
Net current-period Other comprehensive (income) loss attributable to noncontrolling interests	(160)	(134)	(309)	(254)
Ending balance	(29,911)	(12,730)	(29,911)	(12,730)
Unrealized Gains (Losses) on Derivative Instruments | Interest Expense
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,572	2,046	4,619	3,947
Unrealized Gains (Losses) on Derivative Instruments | Other income and (expense)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(207)	(606)	(94)	(1,313)
Unrealized Appreciation (Depreciation) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(367)	(446)	(391)	(470)
Other comprehensive (loss) income before reclassifications	23	23	47	47
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Net current-period Other comprehensive income (loss)	23	23	47	47
Net current-period Other comprehensive (income) loss attributable to noncontrolling interests	0	0	0	0
Ending balance	(344)	(423)	(344)	(423)
Unrealized Appreciation (Depreciation) on Marketable Securities | Interest Expense
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Unrealized Appreciation (Depreciation) on Marketable Securities | Other income and (expense)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	19,309	(34,125)	20,695	(9,008)
Other comprehensive (loss) income before reclassifications	(6,042)	8,612	(7,432)	(16,863)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Net current-period Other comprehensive income (loss)	(6,042)	8,612	(7,432)	(16,863)
Net current-period Other comprehensive (income) loss attributable to noncontrolling interests	93	(123)	97	235
Ending balance	13,360	(25,636)	13,360	(25,636)
Foreign Currency Translation Adjustments | Interest Expense
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Foreign Currency Translation Adjustments | Other income and (expense)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 0	$ 0	$ 0	$ 0