Loans Receivable, Net - Risk Category of Loans by Loan Portfolio Segment Excluding PCI Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Loan	$ 1,750,616	$ 962,772
Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	522,634	307,509
Commercial Real Estate - Investor [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	1,009,510	510,725
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	218,472	144,538
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	1,718,259	925,752
Pass [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	503,466	288,701
Pass [Member] | Commercial Real Estate - Investor [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	998,395	494,664
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	216,398	142,387
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	6,472	12,857
Special Mention [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	5,342	1,803
Special Mention [Member] | Commercial Real Estate - Investor [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan		10,267
Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	1,130	787
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	25,885	24,163
Substandard [Member] | Commercial Real Estate - Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	13,826	17,005
Substandard [Member] | Commercial Real Estate - Investor [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	11,115	5,794
Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	$ 944	$ 1,364