Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	$ 32,222	$ 34,477
Joint venture cash flow hedges	(4,634)	(3,841)
Unrecognized losses of employee benefit plans, net of tax	(137,543)	(144,084)
Total	$ (109,955)	$ (113,448)