Employee Benefit Plans (Net Periodic Benefit Costs) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service costs	$ 282	$ 519	$ 734
Interest costs	9,116	8,079	13,261
Expected return on plan assets	0	0	(4,740)
Amortization of net actuarial loss	3,661	4,828	17,742
Amortization of prior service credit	(4,070)	(4,178)	(4,312)
Settlement costs	0	0	152,388
Net periodic costs	$ 8,989	$ 9,248	$ 175,073