Employee Benefit Plans (Net Periodic Benefit Cost (Benefit)) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Expected return on plan assets, net of expenses	$ (11,558)	$ (11,932)	$ (12,514)
Interest cost on projected benefit obligation	6,958	8,210	8,002
Net amortization and deferral	6,247	6,995	2,687
SERP settlement costs	1,027	0	0
Net periodic expense (benefit)	$ 2,674	$ 3,273	$ (1,825)