Accumulated Other Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	$ 40,302	[1]	$ 34,477	[1]
Joint venture cash flow hedges	(2,636)		(3,841)
Unrecognized components of employee benefit plans, net of tax	(140,944)		(144,084)
Total	$ (103,278)		$ (113,448)

[1] During the three months ended March 31, 2012, the increase in net foreign currency translation adjustments was due to the strengthening of the New Zealand dollar against the U.S. dollar.