Loans Held for Sale - Summary of Loans Held for Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Loans Held For Sale [Line Items]
Loans held for sale	$ 217,667	$ 213,490	$ 11,398
Reclassified From Loans held For Investment [Member]
Loans Held For Sale [Line Items]
Loans held for sale	197,380	197,928
Commercial Loan [Member] | Reclassified From Loans held For Investment [Member]
Loans Held For Sale [Line Items]
Loans held for sale	47,251	45,500
Commercial Real Estate [Member] | Reclassified From Loans held For Investment [Member]
Loans Held For Sale [Line Items]
Loans held for sale	31,277	30,690
Residential Real Estate [Member] | Reclassified From Loans held For Investment [Member]
Loans Held For Sale [Line Items]
Loans held for sale	65,716	71,680
Consumer Loan [Member] | Reclassified From Loans held For Investment [Member]
Loans Held For Sale [Line Items]
Loans held for sale	$ 53,136	$ 50,058