Employee Benefit Plans (Net Periodic Costs) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service costs	$ 71	$ 130	$ 141	$ 260
Interest costs	2,279	2,018	4,558	4,036
Amortization of net actuarial loss	915	1,205	1,830	2,410
Amortization of prior service credit	(1,017)	(1,045)	(2,035)	(2,090)
Net periodic costs	$ 2,248	$ 2,308	$ 4,494	$ 4,616