Disclosure of accumulated other comprehensive loss (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Foreign currency translation adjustment	$ (29,775)	$ (28,829)
Pension and postretirement benefit plans	(320,808)	(333,287)
Tax effect	113,779	117,229
Net of tax amount	(207,029)	(216,058)
Unrealized holding gains on securities available-for-sale	204,640	230,746
Tax effect	(23,433)	(27,668)
Net of tax amount	181,207	203,078
Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Pretax	(1,408)	(1,057)
Tax effect	422	318
Net of tax amount	(986)	(739)
Accumulated other comprehensive income (loss)	$ (56,583)	$ (42,548)