Fair Value of Financial Instruments - Carrying Amount and Estimated Fair Value of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financial assets:
Loans, net	$ 2,447,455	$ 1,966,592
Financial liabilities:
Deposits	3,000,061	2,624,883
Other borrowings	194,572
Carrying Amount [Member]
Financial assets:
Loans, net	2,435,067	1,934,754
Financial liabilities:
Deposits	2,999,231	2,624,663
Other borrowings	194,572
Level 1 [Member]
Financial assets:
Loans, net
Financial liabilities:
Deposits
Other borrowings
Level 2 [Member]
Financial assets:
Loans, net	1,565,919	1,406,366
Financial liabilities:
Deposits	3,000,061	2,624,883
Other borrowings	194,572
Level 3 [Member]
Financial assets:
Loans, net	881,536	560,226
Financial liabilities:
Deposits
Other borrowings