Equity (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss) balance at beginning of period	$ (24,191)	$ (130)	$ 10,592
Accumulated Other Comprehensive Income (Loss), change	17,358	(24,061)	(10,722)
Accumulated Other Comprehensive Income (Loss) balance at end of period	(6,833)	(24,191)	(130)
Currency Translation
Accumulated Other Comprehensive Income (Loss) balance at beginning of period	(17,770)	(11,978)	4,874
Accumulated Other Comprehensive Income (Loss), change	18,254	(5,792)	(16,852)
Accumulated Other Comprehensive Income (Loss) balance at end of period	484	(17,770)	(11,978)
Other
Accumulated Other Comprehensive Income (Loss) balance at beginning of period	3,223	11,918	11,223
Accumulated Other Comprehensive Income (Loss), change	(1,862)	(8,695)	695
Accumulated Other Comprehensive Income (Loss) balance at end of period	1,361	3,223	11,918
Interest Rate Swaps
Accumulated Other Comprehensive Income (Loss) balance at beginning of period	(9,644)	(70)	(5,505)
Accumulated Other Comprehensive Income (Loss), change	966	(9,574)	5,435
Accumulated Other Comprehensive Income (Loss) balance at end of period	$ (8,678)	$ (9,644)	$ (70)