INCOME TAXES (Reconcilements Between Statutory Federal Income Tax Rate And Effective Tax Rate) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax expense at federal statutory rate									$ 25,194	$ 23,584	$ 19,523
Increase (decrease) resulting from:
Tax exempt income, net									(3,606)	(3,457)	(3,468)
Bank-owned life insurance									(862)	(900)	(855)
State income taxes, net of federal income tax benefits									2,965	2,687	2,182
Other, net									49	113	200
Total income tax expense (benefit)	$ 6,879	$ 6,734	$ 5,008	$ 5,119	$ 6,372	$ 5,175	$ 5,014	$ 5,466	$ 23,740	$ 22,027	$ 17,582
Income tax expense at federal statutory rate									35.00%	35.00%	35.00%
Increase (decrease) resulting from:
Tax exempt income, net									(5.00%)	(5.10%)	(6.20%)
Bank-owned life insurance									(1.10%)	(1.30%)	(1.50%)
State income taxes, net of federal income tax benefits									4.10%	4.00%	3.90%
Other, net									0.00%	0.10%	0.40%
Total income tax expense (benefit) and rate									33.00%	32.70%	31.60%