Loans Receivable, Net - Risk Category of Loans by Loan Portfolio Segment Excluding PCI Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loan	$ 1,848,904	$ 1,818,858
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	531,325	534,214
Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	1,111,989	1,132,075
Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	205,590	152,569
Pass
Financing Receivable, Recorded Investment [Line Items]
Loan	1,791,384	1,758,873
Pass | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	505,907	501,652
Pass | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	1,082,896	1,106,747
Pass | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	202,581	150,474
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loan	16,307	9,150
Special Mention | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	8,957	7,680
Special Mention | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	5,666	713
Special Mention | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	1,684	757
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loan	41,102	50,835
Substandard | Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Loan	16,461	24,882
Substandard | Commercial Real Estate - Investor
Financing Receivable, Recorded Investment [Line Items]
Loan	23,427	24,615
Substandard | Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Loan	1,214	1,338
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loan	111	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	$ 111	$ 0