Allowance for Loan Losses ("ALL") - Summary of Investment in Impaired Loans (Detail) (USD $) | Jun. 30, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified |
New loans [Member] | Real estate loans [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 1,549,786 | 1,124,498 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 7,830 | 4,415 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Real estate loans [Member] | Commercial real estate [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 892,999 | 669,711 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 4,262 | 2,149 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Real estate loans [Member] | 1- 4 single family residential [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 523,987 | 359,818 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 2,212 | 1,306 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Real estate loans [Member] | Construction, land and development [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 123,169 | 75,666 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 1,275 | 834 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Real estate loans [Member] | Home equity loans and lines of credit [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 9,631 | 19,303 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 81 | 126 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Other loans [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 756,551 | 646,213 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 4,584 | 3,870 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Other loans [Member] | Commercial and industrial [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 753,984 | 645,037 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 4,559 | 3,853 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
New loans [Member] | Other loans [Member] | Consumer [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 2,567 | 1,176 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 25 | 17 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
Acquired loans [Member] | Real estate loans [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | 4,850 | 5,709 |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 261,870 | 29,168 |
Loans - Recorded Investment, ASC 310-30 Loans | 588,166 | 386,828 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | 149 |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 54 | 52 |
Allowance for Credit Loss, ASC 310-30 Loans | 3,750 | 3,745 |
Acquired loans [Member] | Real estate loans [Member] | Commercial real estate [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | 4,666 | 5,134 |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 85,995 | 7,571 |
Loans - Recorded Investment, ASC 310-30 Loans | 413,154 | 274,147 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 15 | 10 |
Allowance for Credit Loss, ASC 310-30 Loans | 2,883 | 2,675 |
Acquired loans [Member] | Real estate loans [Member] | 1- 4 single family residential [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | 189 |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 111,056 | 9,985 |
Loans - Recorded Investment, ASC 310-30 Loans | 98,802 | 56,745 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | 44 |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 7 | 8 |
Allowance for Credit Loss, ASC 310-30 Loans | 207 | 85 |
Acquired loans [Member] | Real estate loans [Member] | Construction, land and development [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 8,077 | ' |
Loans - Recorded Investment, ASC 310-30 Loans | 76,210 | 55,936 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, ASC 310-30 Loans | 660 | 985 |
Acquired loans [Member] | Real estate loans [Member] | Home equity loans and lines of credit [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | 184 | 386 |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 56,742 | 11,612 |
Loans - Recorded Investment, ASC 310-30 Loans | ' | ' |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | 105 |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 32 | 34 |
Allowance for Credit Loss, ASC 310-30 Loans | ' | ' |
Acquired loans [Member] | Other loans [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 17,640 | 5,329 |
Loans - Recorded Investment, ASC 310-30 Loans | 84,789 | 61,039 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 9 | 6 |
Allowance for Credit Loss, ASC 310-30 Loans | 1,657 | 2,496 |
Acquired loans [Member] | Other loans [Member] | Commercial and industrial [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 16,519 | 5,040 |
Loans - Recorded Investment, ASC 310-30 Loans | 81,444 | 57,047 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 6 | 6 |
Allowance for Credit Loss, ASC 310-30 Loans | 1,359 | 2,339 |
Acquired loans [Member] | Other loans [Member] | Consumer [Member] | ' | ' |
Financing Receivable, Impaired [Line Items] | ' | ' |
Loans - Recorded Investment, Individually Evaluated for Impairment | ' | ' |
Loans - Recorded Investment, Collectively Evaluated for Impairment | 1,121 | 289 |
Loans - Recorded Investment, ASC 310-30 Loans | 3,345 | 3,992 |
Allowance for Credit Loss, Individually Evaluated for Impairment | ' | ' |
Allowance for Credit Loss, Collectively Evaluated for Impairment | 3 | ' |
Allowance for Credit Loss, ASC 310-30 Loans | $298 | $157 |