Equity (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	$ (50,261)	$ (18,212)	$ (35,366)	$ (32,601)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	10,032	(33,348)	(6,057)	(19,080)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1,440	823	2,634	944
Total other comprehensive (loss) income	11,472	(32,525)	(3,423)	(18,136)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(38,789)	(50,737)	(38,789)	(50,737)
Interest Expense AOCI reclass
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,046	898	3,947	1,775
Other (Income) And Expense
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(606)	(75)	(1,313)	(831)
Gains and Losses on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(15,690)	(14,416)	(25,888)	(8,765)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	1,520	2,516	10,524	(3,256)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1,440	69	2,634	190
Total other comprehensive (loss) income	2,960	2,585	13,158	(3,066)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(12,730)	(11,831)	(12,730)	(11,831)
Gains and Losses on Derivative Instruments | Interest Expense AOCI reclass
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,046	898	3,947	1,775
Gains and Losses on Derivative Instruments | Other (Income) And Expense
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(606)	(829)	(1,313)	(1,585)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(446)	(1,506)	(470)	(1,506)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	23	229	47	229
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	754	0	754
Total other comprehensive (loss) income	23	983	47	983
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(423)	(523)	(423)	(523)
Unrealized Gains and Losses on Marketable Securities | Interest Expense AOCI reclass
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Unrealized Gains and Losses on Marketable Securities | Other (Income) And Expense
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	754	0	754
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(34,125)	(2,290)	(9,008)	(22,330)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	8,489	(36,093)	(16,628)	(16,053)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Total other comprehensive (loss) income	8,489	(36,093)	(16,628)	(16,053)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(25,636)	(38,383)	(25,636)	(38,383)
Accumulated Translation Adjustment | Interest Expense AOCI reclass
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0	0	0
Accumulated Translation Adjustment | Other (Income) And Expense
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 0	$ 0	$ 0	$ 0