Fair Value Measurements (Impaired Loans Remeasured and Reported at Fair Value of Underlying Collateral) (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of impaired loans before allocations	$ 77,478	$ 53,591	$ 48,462
Specific valuation allowance allocations	(4,378)	(1,680)	(6,926)
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of impaired loans before allocations	0	0	9,374
Specific valuation allowance allocations	0	0	(2,785)
Fair value	0	0	6,589
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of impaired loans before allocations	14,921	2,715	0
Specific valuation allowance allocations	(2,765)	(1,475)	0
Fair value	$ 12,156	$ 1,240	$ 0