Amounts Recognized in Accumulated Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Defined Benefit
Schedule of Pension and Other Postretirment Benefits Recgonized in Accumulated Other Comprehensive Income (Loss) [Line Items]
Net actuarial loss	$ 70,615	$ 99,129
Net prior service cost	(2,684)	(2,780)
Pretax AOCI	67,931	96,349
Less deferred taxes	18,974	25,972
Post tax AOCI	48,957	70,377
Other Postretirement Benefit Plans, Defined Benefit
Schedule of Pension and Other Postretirment Benefits Recgonized in Accumulated Other Comprehensive Income (Loss) [Line Items]
Net actuarial loss	1,557	4,569
Net prior service cost	9	0
Pretax AOCI	1,566	4,569
Less deferred taxes	605	1,764
Post tax AOCI	$ 961	$ 2,805