Fair Value Measurement - Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Impaired Originated & PNCI Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 1,318		$ 1,318		$ 4,649
Fair Value Nonrecurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,714	$ 6,567	2,714	$ 6,567	6,189
Total Gains/(Losses)	431	184	316	(88)	(762)
Fair Value Nonrecurring Basis [Member] | Impaired Originated & PNCI Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,318	3,377	1,318	3,377	4,649
Total Gains/(Losses)	431	(22)	316	151	(660)
Fair Value Nonrecurring Basis [Member] | Foreclosed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,396	3,190	1,396	3,190	1,540
Total Gains/(Losses)		206		(239)	(102)
Fair Value Nonrecurring Basis [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,714	6,567	2,714	6,567	6,189
Fair Value Nonrecurring Basis [Member] | Level 3 [Member] | Impaired Originated & PNCI Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,318	3,377	1,318	3,377	4,649
Fair Value Nonrecurring Basis [Member] | Level 3 [Member] | Foreclosed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 1,396	$ 3,190	$ 1,396	$ 3,190	$ 1,540