Employer Sponsored Benefit Plan (Plan Assets and Benefit Obligations) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance sheet amounts:
Noncurrent liabilities	$ (14,729)	$ (14,222)
Domestic Pension Plan
Change in benefit obligation:
Net benefit obligation at beginning of year	48,081	50,827
Interest cost	2,139	2,066	$ 2,348
Actuarial loss (gain)	2,062	(2,430)
Gross benefits paid	(2,196)	(2,382)
Net benefit obligation at end of year	50,086	48,081	50,827
Change in plan assets:
Fair value of plan assets at beginning of year	35,413	33,275
Actual return on plan assets	221	(1,106)
Contributions	3,600	5,626
Gross benefits paid	(2,196)	(2,382)
Fair value of plan assets at end of year	37,038	35,413	$ 33,275
Net benefit obligation in excess of plan assets	(13,048)	(12,668)
Balance sheet amounts:
Noncurrent liabilities	(13,048)	(12,668)
Total liabilities	(13,048)	(12,668)
Amounts recognized in accumulated other comprehensive income, net of tax consist of:
Net actuarial loss	19,689	17,313
Net amount recognized	$ 19,689	$ 17,313