Employee Benefit Plans (Net Periodic Cost) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service costs	$ 70	$ 130
Interest costs	2,279	2,018
Amortization of net actuarial loss	915	1,205
Amortization of prior service credit	(1,018)	(1,045)
Net periodic cost	$ 2,246	$ 2,308