Loans Receivable, Net - Risk Category of Loans by Loan Portfolio Segment Excluding PCI Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loan	$ 1,870,747	$ 1,818,858
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	556,180	534,214
Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	1,120,942	1,132,075
Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	193,625	152,569
Pass
Financing Receivable, Recorded Investment [Line Items]
Loan	1,808,968	1,758,873
Pass | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	534,237	501,652
Pass | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	1,087,710	1,106,747
Pass | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	187,021	150,474
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loan	18,715	9,150
Special Mention | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	4,419	7,680
Special Mention | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	10,749	713
Special Mention | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	3,547	757
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loan	43,064	50,835
Substandard | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	17,524	24,882
Substandard | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	22,483	24,615
Substandard | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	3,057	1,338
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loan	0	0
Doubtful | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	0	0
Doubtful | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	0	0
Doubtful | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	$ 0	$ 0