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Allowance for Loan Losses - Recorded Investment in Commercial Loan Classes by Internally Assigned Risk Ratings (Details) - Commercial - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 4,561,391 | $ 4,355,395
Total percentage of recorded investment in commercial loan | 100.00% | 100.00%
Pass |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 4,353,041 | $ 4,169,721
Total percentage of recorded investment in commercial loan | 95.40% | 95.70%
Special Mention |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 120,574 | $ 88,198
Total percentage of recorded investment in commercial loan | 2.60% | 2.00%
Substandard |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 87,776 | $ 97,476
Total percentage of recorded investment in commercial loan | 2.00% | 2.30%
Commercial Real Estate |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 2,681,693 | $ 2,498,476
Total percentage of recorded investment in commercial loan | 100.00% | 100.00%
Commercial Real Estate | Pass |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 2,587,393 | $ 2,423,742
Total percentage of recorded investment in commercial loan | 96.50% | 97.00%
Commercial Real Estate | Special Mention |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 55,218 | $ 33,098
Total percentage of recorded investment in commercial loan | 2.10% | 1.30%
Commercial Real Estate | Substandard |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 39,082 | $ 41,636
Total percentage of recorded investment in commercial loan | 1.40% | 1.70%
Commercial and Industrial |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 1,446,811 | $ 1,401,035
Total percentage of recorded investment in commercial loan | 100.00% | 100.00%
Commercial and Industrial | Pass |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 1,354,269 | $ 1,315,507
Total percentage of recorded investment in commercial loan | 93.60% | 93.90%
Commercial and Industrial | Special Mention |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 53,853 | $ 40,409
Total percentage of recorded investment in commercial loan | 3.70% | 2.90%
Commercial and Industrial | Substandard |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 38,689 | $ 45,119
Total percentage of recorded investment in commercial loan | 2.70% | 3.20%
Commercial Construction |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 432,887 | $ 455,884
Total percentage of recorded investment in commercial loan | 99.99% | 100.00%
Commercial Construction | Pass |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 411,379 | $ 430,472
Total percentage of recorded investment in commercial loan | 95.00% | 94.40%
Commercial Construction | Special Mention |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 11,503 | $ 14,691
Total percentage of recorded investment in commercial loan | 2.70% | 3.20%
Commercial Construction | Substandard |  |
Financing Receivable, Recorded Investment [Line Items] |  |
Loans and leases receivables, recorded investment | $ 10,005 | $ 10,721
Total percentage of recorded investment in commercial loan | 2.30% | 2.40%

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- Definition Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522 + Details
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