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Allowance for Loan Losses (Tables) | 12 Months Ended
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Dec. 31, 2017
Receivables [Abstract] |
Age Analysis of Past Due Loans Segregated by Class of Loans | The following tables present the age analysis of past due loans segregated by class of loans as of the dates presented:
| December 31, 2017
(dollars in thousands) | Current |  |  | 30-59 Days Past Due |  |  | 60-89 Days Past Due |  |  | Non- performing |  |  | Total Past Due Loans |  |  | Total Loans |
Commercial real estate | $ | 2,681,395 |  |  | $ | 997 |  |  | $ | 134 |  |  | $ | 3,468 |  |  | $ | 4,599 |  |  | $ | 2,685,994 |
Commercial and industrial | 1,426,754 |  |  | 420 |  |  | 446 |  |  | 5,646 |  |  | 6,512 |  |  | 1,433,266 |
Commercial construction | 377,968 |  |  | 2,473 |  |  | 20 |  |  | 3,873 |  |  | 6,366 |  |  | 384,334 |
Residential mortgage | 687,195 |  |  | 2,975 |  |  | 1,439 |  |  | 7,165 |  |  | 11,579 |  |  | 698,774 |
Home equity | 480,956 |  |  | 2,065 |  |  | 590 |  |  | 3,715 |  |  | 6,370 |  |  | 487,326 |
Installment and other consumer | 66,770 |  |  | 193 |  |  | 170 |  |  | 71 |  |  | 434 |  |  | 67,204 |
Consumer construction | 4,551 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 4,551 |
Loans held for sale | 4,485 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 4,485 |
Total | $ | 5,730,074 |  |  | $ | 9,123 |  |  | $ | 2,799 |  |  | $ | 23,938 |  |  | $ | 35,860 |  |  | $ | 5,765,934 |
| December 31, 2016
(dollars in thousands) | Current |  |  | 30-59 Days Past Due |  |  | 60-89 Days Past Due |  |  | Non- performing |  |  | Total Past Due Loans |  |  | Total Loans |
Commercial real estate | $ | 2,479,513 |  |  | $ | 2,032 |  |  | $ | 759 |  |  | $ | 16,172 |  |  | $ | 18,963 |  |  | $ | 2,498,476 |
Commercial and industrial | 1,391,475 |  |  | 1,061 |  |  | 428 |  |  | 8,071 |  |  | 9,560 |  |  | 1,401,035 |
Commercial construction | 450,410 |  |  | 547 |  |  | — |  |  | 4,927 |  |  | 5,474 |  |  | 455,884 |
Residential mortgage | 689,635 |  |  | 1,312 |  |  | 1,117 |  |  | 9,918 |  |  | 12,347 |  |  | 701,982 |
Home equity | 476,866 |  |  | 1,470 |  |  | 509 |  |  | 3,439 |  |  | 5,418 |  |  | 482,284 |
Installment and other consumer | 65,525 |  |  | 176 |  |  | 43 |  |  | 108 |  |  | 327 |  |  | 65,852 |
Consumer construction | 5,906 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 5,906 |
Loans held for sale | 3,793 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 3,793 |
Total | $ | 5,563,123 |  |  | $ | 6,598 |  |  | $ | 2,856 |  |  | $ | 42,635 |  |  | $ | 52,089 |  |  | $ | 5,615,212 |
Recorded Investment in Commercial Loan Classes by Internally Assigned Risk Ratings | The following tables present the recorded investment in commercial loan classes by internally assigned risk ratings as of the dates presented:
| December 31, 2017
(dollars in thousands) | Commercial Real Estate |  |  | % of Total |  |  | Commercial and Industrial |  |  | % of Total |  |  | Commercial Construction |  |  | % of Total |  |  | Total |  |  | % of Total |
Pass | $ | 2,588,847 |  |  | 96.4 | % |  | $ | 1,345,810 |  |  | 93.9 | % |  | $ | 368,105 |  |  | 95.8 | % |  | $ | 4,302,762 |  |  | 95.5 | %
Special mention | 66,436 |  |  | 2.5 | % |  | 54,320 |  |  | 3.8 | % |  | 9,345 |  |  | 2.4 | % |  | 130,101 |  |  | 2.9 | %
Substandard | 30,711 |  |  | 1.1 | % |  | 33,136 |  |  | 2.3 | % |  | 6,884 |  |  | 1.8 | % |  | 70,731 |  |  | 1.6 | %
Total | $ | 2,685,994 |  |  | 100.0 | % |  | $ | 1,433,266 |  |  | 100.0 | % |  | $ | 384,334 |  |  | 100.0 | % |  | $ | 4,503,594 |  |  | 100.0 | %
| December 31, 2016
(dollars in thousands) | Commercial Real Estate |  |  | % of Total |  |  | Commercial and Industrial |  |  | % of Total |  |  | Commercial Construction |  |  | % of Total |  |  | Total |  |  | % of Total |
Pass | $ | 2,423,742 |  |  | 97.0 | % |  | $ | 1,315,507 |  |  | 93.9 | % |  | $ | 430,472 |  |  | 94.4 | % |  | $ | 4,169,721 |  |  | 95.7 | %
Special mention | 33,098 |  |  | 1.3 | % |  | 40,409 |  |  | 2.9 | % |  | 14,691 |  |  | 3.2 | % |  | 88,198 |  |  | 2.0 | %
Substandard | 41,636 |  |  | 1.7 | % |  | 45,119 |  |  | 3.2 | % |  | 10,721 |  |  | 2.4 | % |  | 97,476 |  |  | 2.3 | %
Total | $ | 2,498,476 |  |  | 100.0 | % |  | $ | 1,401,035 |  |  | 100.0 | % |  | $ | 455,884 |  |  | 100.0 | % |  | $ | 4,355,395 |  |  | 100.0 | %
Recorded Investment in Consumer Loan Classes by Performing and Nonperforming Status | The following tables present the recorded investment in consumer loan classes by performing and nonperforming status as of the dates presented:
| December 31, 2017
(dollars in thousands) | Residential Mortgage |  |  | % of Total |  |  | Home Equity |  |  | % of Total |  |  | Installment and other consumer |  |  | % of Total |  |  | Consumer Construction |  |  | % of Total |  |  | Total |  |  | % of Total |
Performing | $ | 691,609 |  |  | 99.0 | % |  | $ | 483,611 |  |  | 99.2 | % |  | $ | 67,133 |  |  | 99.9 | % |  | $ | 4,551 |  |  | 100.0 | % |  | $ | 1,246,904 |  |  | 99.1 | %
Nonperforming | 7,165 |  |  | 1.0 | % |  | 3,715 |  |  | 0.8 | % |  | 71 |  |  | 0.1 | % |  | — |  |  | — | % |  | 10,951 |  |  | 0.9 | %
Total | $ | 698,774 |  |  | 100.0 | % |  | $ | 487,326 |  |  | 100.0 | % |  | $ | 67,204 |  |  | 100.0 | % |  | $ | 4,551 |  |  | 100.0 | % |  | $ | 1,257,855 |  |  | 100.0 | %
| December 31, 2016
(dollars in thousands) | Residential Mortgage |  |  | % of Total |  |  | Home Equity |  |  | % of Total |  |  | Installment and other consumer |  |  | % of Total |  |  | Consumer Construction |  |  | % of Total |  |  | Total |  |  | % of Total |
Performing | $ | 692,064 |  |  | 98.6 | % |  | $ | 478,845 |  |  | 99.3 | % |  | $ | 65,744 |  |  | 99.8 | % |  | $ | 5,906 |  |  | 100.0 | % |  | $ | 1,242,559 |  |  | 98.9 | %
Nonperforming | 9,918 |  |  | 1.4 | % |  | 3,439 |  |  | 0.7 | % |  | 108 |  |  | 0.2 | % |  | — |  |  | — | % |  | 13,465 |  |  | 1.1 | %
Total | $ | 701,982 |  |  | 100.0 | % |  | $ | 482,284 |  |  | 100.0 | % |  | $ | 65,852 |  |  | 100.0 | % |  | $ | 5,906 |  |  | 100.0 | % |  | $ | 1,256,024 |  |  | 100.0 | %
Investments in Loans Considered to be Impaired and Related Information on Impaired Loans | The following table summarizes investments in loans considered to be impaired and related information on those impaired loans for the years presented:
| For the Year Ended
| December 31, 2017 |  | December 31, 2016
(dollars in thousands) | Average Recorded Investment |  |  | Interest Income Recognized |  |  | Average Recorded Investment |  |  | Interest Income Recognized |
With a related allowance recorded: |  |  |  |  |  |  |
Commercial real estate | $ | — |  |  | $ | — |  |  | $ | — |  |  | $ | — |
Commercial and industrial | 968 |  |  | 52 |  |  | 2,438 |  |  | — |
Commercial construction | — |  |  | — |  |  | — |  |  | — |
Consumer real estate | 23 |  |  | 2 |  |  | 28 |  |  | 2 |
Other consumer | 34 |  |  | 2 |  |  | 2 |  |  | — |
Total with a Related Allowance Recorded | 1,025 |  |  | 56 |  |  | 2,468 |  |  | 2 |
Without a related allowance recorded: |  |  |  |  |  |  |
Commercial real estate | 6,636 |  |  | 177 |  |  | 17,496 |  |  | 144 |
Commercial and industrial | 9,897 |  |  | 257 |  |  | 6,141 |  |  | 160 |
Commercial construction | 6,828 |  |  | 253 |  |  | 7,723 |  |  | 162 |
Consumer real estate | 11,037 |  |  | 487 |  |  | 11,939 |  |  | 523 |
Other consumer | 23 |  |  | — |  |  | 35 |  |  | 1 |
Total without a Related Allowance Recorded | 34,421 |  |  | 1,174 |  |  | 43,334 |  |  | 990 |
Total: |  |  |  |  |  |  |
Commercial real estate | 6,636 |  |  | 177 |  |  | 17,496 |  |  | 144 |
Commercial and industrial | 10,865 |  |  | 309 |  |  | 8,579 |  |  | 160 |
Commercial construction | 6,828 |  |  | 253 |  |  | 7,723 |  |  | 162 |
Consumer real estate | 11,060 |  |  | 489 |  |  | 11,967 |  |  | 525 |
Other consumer | 57 |  |  | 2 |  |  | 37 |  |  | 1 |
Total | $ | 35,446 |  |  | $ | 1,230 |  |  | $ | 45,802 |  |  | $ | 992 |
The following tables summarize investments in loans considered to be impaired and related information on those impaired loans as of the dates presented:
| December 31, 2017 |  | December 31, 2016
(dollars in thousands) | Recorded Investment |  |  | Unpaid Principal Balance |  |  | Related Allowance |  |  | Recorded Investment |  |  | Unpaid Principal Balance |  |  | Related Allowance |
With a related allowance recorded: |  |  |  |  |  |  |  |  |  |  |
Commercial real estate | $ | — |  |  | $ | — |  |  | $ | — |  |  | $ | — |  |  | $ | — |  |  | $ | — |
Commercial and industrial | 1,735 |  |  | 1,787 |  |  | 29 |  |  | 964 |  |  | 2,433 |  |  | 771 |
Commercial construction | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |
Consumer real estate | 21 |  |  | 21 |  |  | 21 |  |  | 26 |  |  | 26 |  |  | 26 |
Other consumer | 27 |  |  | 27 |  |  | 27 |  |  | 1 |  |  | 1 |  |  | 1 |
Total with a Related Allowance Recorded | 1,783 |  |  | 1,835 |  |  | 77 |  |  | 991 |  |  | 2,460 |  |  | 798 |
Without a related allowance recorded: |  |  |  |  |  |  |  |  |  |  |
Commercial real estate | 3,546 |  |  | 3,811 |  |  | — |  |  | 16,352 |  |  | 17,654 |  |  | — |
Commercial and industrial | 5,549 |  |  | 7,980 |  |  | — |  |  | 5,902 |  |  | 7,699 |  |  | — |
Commercial construction | 5,464 |  |  | 8,132 |  |  | — |  |  | 6,613 |  |  | 10,306 |  |  | — |
Consumer real estate | 10,467 |  |  | 11,357 |  |  | — |  |  | 12,053 |  |  | 12,849 |  |  | — |
Other consumer | 14 |  |  | 22 |  |  | — |  |  | 24 |  |  | 31 |  |  | — |
Total without a Related Allowance Recorded | 25,040 |  |  | 31,302 |  |  | — |  |  | 40,944 |  |  | 48,539 |  |  | — |
Total: |  |  |  |  |  |  |  |  |  |  |
Commercial real estate | 3,546 |  |  | 3,811 |  |  | — |  |  | 16,352 |  |  | 17,654 |  |  | — |
Commercial and industrial | 7,284 |  |  | 9,767 |  |  | 29 |  |  | 6,866 |  |  | 10,132 |  |  | 771 |
Commercial construction | 5,464 |  |  | 8,132 |  |  | — |  |  | 6,613 |  |  | 10,306 |  |  | — |
Consumer real estate | 10,488 |  |  | 11,378 |  |  | 21 |  |  | 12,079 |  |  | 12,875 |  |  | 26 |
Other consumer | 41 |  |  | 49 |  |  | 27 |  |  | 25 |  |  | 32 |  |  | 1 |
Total | $ | 26,823 |  |  | $ | 33,137 |  |  | $ | 77 |  |  | $ | 41,935 |  |  | $ | 50,999 |  |  | $ | 798 |
Summary of Allowance for Loan Losses | The following tables detail activity in the ALL for the periods presented:
| 2017
(dollars in thousands) | Commercial Real Estate |  |  | Commercial and Industrial |  |  | Commercial Construction |  |  | Consumer Real Estate |  |  | Other Consumer |  |  | Total Loans |
Balance at beginning of year | $ | 19,976 |  |  | $ | 10,810 |  |  | $ | 13,999 |  |  | $ | 6,095 |  |  | $ | 1,895 |  |  | $ | 52,775 |
Charge-offs | (2,304 | ) |  | (4,709 | ) |  | (2,571 | ) |  | (2,274 | ) |  | (1,638 | ) |  | (13,496 | )
Recoveries | 810 |  |  | 654 |  |  | 851 |  |  | 342 |  |  | 571 |  |  | 3,228 |
Net (Charge-offs) Recoveries | (1,494 | ) |  | (4,055 | ) |  | (1,720 | ) |  | (1,932 | ) |  | (1,067 | ) |  | (10,268 | )
Provision for loan losses | 8,753 |  |  | 2,211 |  |  | 888 |  |  | 1,316 |  |  | 715 |  |  | 13,883 |
Balance at End of Year | $ | 27,235 |  |  | $ | 8,966 |  |  | $ | 13,167 |  |  | $ | 5,479 |  |  | $ | 1,543 |  |  | $ | 56,390 |
| 2016
(dollars in thousands) | Commercial Real Estate |  |  | Commercial and Industrial |  |  | Commercial Construction |  |  | Consumer Real Estate |  |  | Other Consumer |  |  | Total Loans |
Balance at beginning of year | $ | 15,043 |  |  | $ | 10,853 |  |  | $ | 12,625 |  |  | $ | 8,400 |  |  | $ | 1,226 |  |  | $ | 48,147 |
Charge-offs | (3,114 | ) |  | (6,810 | ) |  | (1,877 | ) |  | (1,657 | ) |  | (2,103 | ) |  | (15,561 | )
Recoveries | 692 |  |  | 722 |  |  | 21 |  |  | 433 |  |  | 356 |  |  | 2,224 |
Net Recoveries (Charge-offs) | (2,422 | ) |  | (6,088 | ) |  | (1,856 | ) |  | (1,224 | ) |  | (1,747 | ) |  | (13,337 | )
Provision for loan losses | 7,355 |  |  | 6,045 |  |  | 3,230 |  |  | (1,081 | ) |  | 2,416 |  |  | 17,965 |
Balance at End of Year | $ | 19,976 |  |  | $ | 10,810 |  |  | $ | 13,999 |  |  | $ | 6,095 |  |  | $ | 1,895 |  |  | $ | 52,775 |
Summary of Allowance for Loan Losses and Recorded Investments | The following tables present the ALL and recorded investments in loans by category as of December 31:
| 2017
| Allowance for Loan Losses |  | Portfolio Loans
(dollars in thousands) | Individually Evaluated for Impairment |  |  | Collectively Evaluated for Impairment |  |  | Total |  |  | Individually Evaluated for Impairment |  |  | Collectively Evaluated for Impairment |  |  | Total |
Commercial real estate | $ | — |  |  | $ | 27,235 |  |  | $ | 27,235 |  |  | $ | 3,546 |  |  | $ | 2,682,448 |  |  | $ | 2,685,994 |
Commercial and industrial | 29 |  |  | 8,937 |  |  | 8,966 |  |  | 7,284 |  |  | 1,425,982 |  |  | 1,433,266 |
Commercial construction | — |  |  | 13,167 |  |  | 13,167 |  |  | 5,464 |  |  | 378,870 |  |  | 384,334 |
Consumer real estate | 21 |  |  | 5,458 |  |  | 5,479 |  |  | 10,488 |  |  | 1,180,163 |  |  | 1,190,651 |
Other consumer | 27 |  |  | 1,516 |  |  | 1,543 |  |  | 41 |  |  | 67,163 |  |  | 67,204 |
Total | $ | 77 |  |  | $ | 56,313 |  |  | $ | 56,390 |  |  | $ | 26,823 |  |  | $ | 5,734,626 |  |  | $ | 5,761,449 |
| 2016
| Allowance for Loan Losses |  | Portfolio Loans
(dollars in thousands) | Individually Evaluated for Impairment |  |  | Collectively Evaluated for Impairment |  |  | Total |  |  | Individually Evaluated for Impairment |  |  | Collectively Evaluated for Impairment |  |  | Total |
Commercial real estate | $ | — |  |  | $ | 19,976 |  |  | $ | 19,976 |  |  | $ | 16,352 |  |  | $ | 2,482,124 |  |  | $ | 2,498,476 |
Commercial and industrial | 771 |  |  | 10,039 |  |  | 10,810 |  |  | 6,866 |  |  | 1,394,169 |  |  | 1,401,035 |
Commercial construction | — |  |  | 13,999 |  |  | 13,999 |  |  | 6,613 |  |  | 449,271 |  |  | 455,884 |
Consumer real estate | 26 |  |  | 6,069 |  |  | 6,095 |  |  | 12,079 |  |  | 1,178,093 |  |  | 1,190,172 |
Other consumer | 1 |  |  | 1,894 |  |  | 1,895 |  |  | 25 |  |  | 65,827 |  |  | 65,852 |
Total | $ | 798 |  |  | $ | 51,977 |  |  | $ | 52,775 |  |  | $ | 41,935 |  |  | $ | 5,569,484 |  |  | $ | 5,611,419 |

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- Definition Tabular disclosure of financing receivables by credit quality indicator. The credit quality indicator is a statistic about the credit quality of financing receivables. Examples include, but not limited to, consumer credit risk scores, credit-rating-agency ratings, an entity's internal credit risk grades, loan-to-value ratios, collateral, collection experience and other internal metrics. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 55 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=82894031&loc=SL6953803-111525 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 29 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953659-111524 + Details
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- Definition Tabular disclosure of financing receivables that are past due but not impaired, financing receivables that are 90 days past due and still accruing, and financing receivables on nonaccrual status. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524 + Details
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