Employer Sponsored Benefit Plan (Plan Assets and Benefit Obligations) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Change in benefit obligation:
Net benefit obligation at beginning of year	$ 60,020	$ 52,841
Interest cost	2,453	2,583	2,589
Actuarial (gain) loss	(6,900)	6,561
Gross benefits paid	(2,146)	(1,965)
Net benefit obligation at end of year	53,427	60,020	52,841
Change in plan assets:
Fair value of plan assets at beginning of year	36,355	32,643
Actual return on plan assets	5,226	3,562
Contributions	1,245	2,115
Gross benefits paid	(2,146)	(1,965)
Fair value of plan assets at end of year	40,680	36,355	32,643
Net benefit obligation in excess of plan assets	(12,747)	(23,665)
Balance sheet amounts:
Noncurrent liabilities	(12,747)	(23,665)
Total liabilities	(12,747)	(23,665)
Amounts recognized in accumulated other comprehensive income, net of tax consist of:
Net actuarial loss	14,830	21,342
Net amount recognized	$ 14,830	$ 21,342