Loans | Loans The period end loan composition was as follows. June 30, December 31, ($ in Thousands) Commercial and industrial $ 6,701,986 $ 6,190,683 Commercial real estate — owner occupied 921,736 918,212 Commercial and business lending 7,623,722 7,108,895 Commercial real estate — investor 3,495,791 3,234,266 Real estate construction 1,285,573 1,162,145 Commercial real estate lending 4,781,364 4,396,411 Total commercial 12,405,086 11,505,306 Residential mortgage 6,035,720 5,783,267 Home equity 968,771 1,005,802 Other consumer 405,709 419,968 Total consumer 7,410,200 7,209,037 Total loans $ 19,815,286 $ 18,714,343 The following table presents commercial and consumer loans by credit quality indicator at June 30, 2016 . Pass Special Mention Potential Problem Nonaccrual Total ($ in Thousands) Commercial and industrial $ 5,910,730 $ 217,999 $ 379,818 $ 193,439 $ 6,701,986 Commercial real estate - owner occupied 826,327 40,103 45,671 9,635 921,736 Commercial and business lending 6,737,057 258,102 425,489 203,074 7,623,722 Commercial real estate - investor 3,436,680 22,502 25,081 11,528 3,495,791 Real estate construction 1,281,526 973 2,117 957 1,285,573 Commercial real estate lending 4,718,206 23,475 27,198 12,485 4,781,364 Total commercial 11,455,263 281,577 452,687 215,559 12,405,086 Residential mortgage 5,975,297 4,170 3,953 52,300 6,035,720 Home equity 952,727 1,587 94 14,363 968,771 Other consumer 404,894 435 — 380 405,709 Total consumer 7,332,918 6,192 4,047 67,043 7,410,200 Total $ 18,788,181 $ 287,769 $ 456,734 $ 282,602 $ 19,815,286 The following table presents commercial and consumer loans by credit quality indicator at December 31, 2015 . Pass Special Mention Potential Problem Nonaccrual Total ($ in Thousands) Commercial and industrial $ 5,522,809 $ 341,169 $ 233,130 $ 93,575 $ 6,190,683 Commercial real estate - owner occupied 835,572 38,885 35,706 8,049 918,212 Commercial and business lending 6,358,381 380,054 268,836 101,624 7,108,895 Commercial real estate - investor 3,153,703 45,976 25,944 8,643 3,234,266 Real estate construction 1,157,034 252 3,919 940 1,162,145 Commercial real estate lending 4,310,737 46,228 29,863 9,583 4,396,411 Total commercial 10,669,118 426,282 298,699 111,207 11,505,306 Residential mortgage 5,727,437 1,552 2,796 51,482 5,783,267 Home equity 988,574 1,762 222 15,244 1,005,802 Other consumer 419,087 556 — 325 419,968 Total consumer 7,135,098 3,870 3,018 67,051 7,209,037 Total $ 17,804,216 $ 430,152 $ 301,717 $ 178,258 $ 18,714,343 Factors that are important to managing overall credit quality are sound loan underwriting and administration, systematic monitoring of existing loans and commitments, effective loan review on an ongoing basis, early identification of potential problems, and appropriate allowance for loan losses, allowance for unfunded commitments, nonaccrual, and charge off policies. For commercial loans, management has determined the pass credit quality indicator to include credits that exhibit acceptable financial statements, cash flow, and leverage. If any risk exists, it is mitigated by the loan structure, collateral, monitoring, or control. For consumer loans, performing loans include credits that are performing in accordance with the original contractual terms. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Special mention credits have potential weaknesses that deserve management’s attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the credit. Potential problem loans are considered inadequately protected by the current net worth and paying capacity of the obligor or the collateral pledged. These loans generally have a well-defined weakness, or weaknesses, that may jeopardize liquidation of the debt and are characterized by the distinct possibility that the Corporation will sustain some loss if the deficiencies are not corrected. Lastly, management considers a loan to be impaired when it is probable that the Corporation will be unable to collect all amounts due according to the original contractual terms of the note agreement, including both principal and interest. Management has determined that commercial and consumer loan relationships that have nonaccrual status or have had their terms restructured in a troubled debt restructuring meet this impaired loan definition. Commercial loans classified as special mention, potential problem, and nonaccrual loans are reviewed at a minimum on a quarterly basis, while pass rated credits are reviewed on an annual basis or more frequently if the loan renewal is less than one year or if otherwise warranted. The following table presents loans by past due status at June 30, 2016 . Current 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due (a) Nonaccrual (b) Total ($ in Thousands) Commercial and industrial $ 6,506,175 $ 1,755 $ 369 $ 248 $ 193,439 $ 6,701,986 Commercial real estate - owner occupied 911,908 193 — — 9,635 921,736 Commercial and business lending 7,418,083 1,948 369 248 203,074 7,623,722 Commercial real estate - investor 3,481,548 2,715 — — 11,528 3,495,791 Real estate construction 1,284,092 427 97 — 957 1,285,573 Commercial real estate lending 4,765,640 3,142 97 — 12,485 4,781,364 Total commercial 12,183,723 5,090 466 248 215,559 12,405,086 Residential mortgage 5,976,038 7,040 342 — 52,300 6,035,720 Home equity 946,678 6,150 1,580 — 14,363 968,771 Other consumer 402,188 1,313 582 1,246 380 405,709 Total consumer 7,324,904 14,503 2,504 1,246 67,043 7,410,200 Total $ 19,508,627 $ 19,593 $ 2,970 $ 1,494 $ 282,602 $ 19,815,286 (a) The recorded investment in loans past due 90 days or more and still accruing totaled $1 million at June 30, 2016 (the same as the reported balances for the accruing loans noted above). (b) Of the total nonaccrual loans, $236 million or 84% were current with respect to payment at June 30, 2016 . The following table presents loans by past due status at December 31, 2015 . Current 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due (a) Nonaccrual (b) Total ($ in Thousands) Commercial and industrial $ 6,095,848 $ 602 $ 409 $ 249 $ 93,575 $ 6,190,683 Commercial real estate - owner occupied 903,021 7,142 — — 8,049 918,212 Commercial and business lending 6,998,869 7,744 409 249 101,624 7,108,895 Commercial real estate - investor 3,225,332 291 — — 8,643 3,234,266 Real estate construction 1,160,909 270 26 — 940 1,162,145 Commercial real estate lending 4,386,241 561 26 — 9,583 4,396,411 Total commercial 11,385,110 8,305 435 249 111,207 11,505,306 Residential mortgage 5,726,855 4,491 439 — 51,482 5,783,267 Home equity 982,639 6,190 1,729 — 15,244 1,005,802 Other consumer 416,374 1,195 675 1,399 325 419,968 Total consumer 7,125,868 11,876 2,843 1,399 67,051 7,209,037 Total $ 18,510,978 $ 20,181 $ 3,278 $ 1,648 $ 178,258 $ 18,714,343 (a) The recorded investment in loans past due 90 days or more and still accruing totaled $2 million at December 31, 2015 (the same as the reported balances for the accruing loans noted above). (b) Of the total nonaccrual loans, $124 million or 69% were current with respect to payment at December 31, 2015 . The following table presents impaired loans at June 30, 2016 . Recorded Unpaid Related Average Interest ($ in Thousands) Loans with a related allowance Commercial and industrial $ 30,866 $ 31,402 $ 675 $ 30,915 $ 443 Commercial real estate — owner occupied 10,746 10,917 622 10,904 189 Commercial and business lending 41,612 42,319 1,297 41,819 632 Commercial real estate — investor 21,983 22,782 694 22,387 943 Real estate construction 1,329 1,801 530 1,356 34 Commercial real estate lending 23,312 24,583 1,224 23,743 977 Total commercial 64,924 66,902 2,521 65,562 1,609 Residential mortgage 64,547 69,517 11,684 65,674 1,151 Home equity 20,668 22,613 9,741 21,092 535 Other consumer 1,286 1,346 254 1,316 18 Total consumer 86,501 93,476 21,679 88,082 1,704 Total loans $ 151,425 $ 160,378 $ 24,200 $ 153,644 $ 3,313 Loans with no related allowance Commercial and industrial $ 191,752 $ 212,763 $ — $ 193,553 $ 348 Commercial real estate — owner occupied 6,398 8,854 — 6,580 — Commercial and business lending 198,150 221,617 — 200,133 348 Commercial real estate — investor 9,736 10,032 — 9,809 — Real estate construction — — — — — Commercial real estate lending 9,736 10,032 — 9,809 — Total commercial 207,886 231,649 — 209,942 348 Residential mortgage 6,067 6,331 — 6,138 96 Home equity 650 651 — 652 20 Other consumer — — — — — Total consumer 6,717 6,982 — 6,790 116 Total loans $ 214,603 $ 238,631 $ — $ 216,732 $ 464 Total Commercial and industrial $ 222,618 $ 244,165 $ 675 $ 224,468 $ 791 Commercial real estate — owner occupied 17,144 19,771 622 17,484 189 Commercial and business lending 239,762 263,936 1,297 241,952 980 Commercial real estate — investor 31,719 32,814 694 32,196 943 Real estate construction 1,329 1,801 530 1,356 34 Commercial real estate lending 33,048 34,615 1,224 33,552 977 Total commercial 272,810 298,551 2,521 275,504 1,957 Residential mortgage 70,614 75,848 11,684 71,812 1,247 Home equity 21,318 23,264 9,741 21,744 555 Other consumer 1,286 1,346 254 1,316 18 Total consumer 93,218 100,458 21,679 94,872 1,820 Total loans (a) $ 366,028 $ 399,009 $ 24,200 $ 370,376 $ 3,777 (a) The net recorded investment (defined as recorded investment, net of the related allowance) of the impaired loans represented 86% of the unpaid principal balance at June 30, 2016 . The following table presents impaired loans at December 31, 2015 . Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized ($ in Thousands) Loans with a related allowance Commercial and industrial $ 57,785 $ 59,409 $ 8,162 $ 46,833 $ 855 Commercial real estate — owner occupied 9,705 9,804 448 10,087 412 Commercial and business lending 67,490 69,213 8,610 56,920 1,267 Commercial real estate — investor 27,822 29,444 1,831 28,278 1,914 Real estate construction 1,450 2,154 453 1,667 66 Commercial real estate lending 29,272 31,598 2,284 29,945 1,980 Total commercial 96,762 100,811 10,894 86,865 3,247 Residential mortgage 66,590 71,084 12,462 68,183 2,374 Home equity 21,769 23,989 10,118 22,624 1,147 Other consumer 1,154 1,225 195 1,199 30 Total consumer 89,513 96,298 22,775 92,006 3,551 Total loans $ 186,275 $ 197,109 $ 33,669 $ 178,871 $ 6,798 Loans with no related allowance Commercial and industrial $ 65,083 $ 72,259 $ — $ 79,573 $ 1,657 Commercial real estate — owner occupied 6,221 6,648 — 6,534 15 Commercial and business lending 71,304 78,907 — 86,107 1,672 Commercial real estate — investor 2,736 2,840 — 2,763 90 Real estate construction — — — — — Commercial real estate lending 2,736 2,840 — 2,763 90 Total commercial 74,040 81,747 — 88,870 1,762 Residential mortgage 4,762 5,033 — 4,726 126 Home equity 544 544 — 544 30 Other consumer — — — — — Total consumer 5,306 5,577 — 5,270 156 Total loans $ 79,346 $ 87,324 $ — $ 94,140 $ 1,918 Total Commercial and industrial $ 122,868 $ 131,668 $ 8,162 $ 126,406 $ 2,512 Commercial real estate — owner occupied 15,926 16,452 448 16,621 427 Commercial and business lending 138,794 148,120 8,610 143,027 2,939 Commercial real estate — investor 30,558 32,284 1,831 31,041 2,004 Real estate construction 1,450 2,154 453 1,667 66 Commercial real estate lending 32,008 34,438 2,284 32,708 2,070 Total commercial 170,802 182,558 10,894 175,735 5,009 Residential mortgage 71,352 76,117 12,462 72,909 2,500 Home equity 22,313 24,533 10,118 23,168 1,177 Other consumer 1,154 1,225 195 1,199 30 Total consumer 94,819 101,875 22,775 97,276 3,707 Total loans (a) $ 265,621 $ 284,433 $ 33,669 $ 273,011 $ 8,716 (a) The net recorded investment (defined as recorded investment, net of the related allowance) of the impaired loans represented 82% of the unpaid principal balance at December 31, 2015 . Troubled Debt Restructurings (“Restructured Loans”): Loans are considered restructured loans if concessions have been granted to borrowers that are experiencing financial difficulty. See Note 1 “Summary of Significant Accounting Policies," in the Corporation’s 2015 Annual Report on Form 10-K for the Corporation's accounting policy for troubled debt restructurings. The Corporation had a recorded investment of $8 million in loans modified in troubled debt restructurings for the six months ended June 30, 2016 , of which approximately $3 million was in accrual status and $5 million was in nonaccrual pending a sustained period of repayment. The following table presents nonaccrual and performing restructured loans by loan portfolio. June 30, 2016 December 31, 2015 Performing Restructured Loans Nonaccrual Restructured Loans (a) Performing Restructured Loans Nonaccrual Restructured Loans (a) ($ in Thousands) Commercial and industrial $ 29,179 $ 2,536 $ 29,293 $ 1,714 Commercial real estate — owner occupied 7,509 2,620 7,877 2,703 Commercial real estate — investor 20,191 957 21,915 3,936 Real estate construction 372 94 510 177 Residential mortgage 18,314 24,479 19,870 24,592 Home equity 6,955 4,127 7,069 4,522 Other consumer 906 28 829 40 Total $ 83,426 $ 34,841 $ 87,363 $ 37,684 (a) Nonaccrual restructured loans have been included within nonaccrual loans. The following table provides the number of loans modified in a troubled debt restructuring by loan portfolio during the six months ended June 30, 2016 and 2015 , and the recorded investment and unpaid principal balance as of June 30, 2016 and 2015 . Six Months Ended June 30, 2016 Six Months Ended June 30, 2015 Number of Loans Recorded Investment (a) Unpaid Principal Balance (b) Number of Loans Recorded Investment (a) Unpaid Principal Balance (b) ($ in Thousands) Commercial and industrial 11 $ 2,608 $ 2,676 6 $ 1,847 $ 2,296 Commercial real estate — owner occupied 1 120 126 5 3,506 3,636 Commercial real estate — investor — — — 1 2,237 2,237 Real estate construction — — — 1 6 6 Residential mortgage 48 3,942 4,171 52 5,249 5,380 Home equity 37 1,433 1,554 49 1,897 1,898 Total 97 $ 8,103 $ 8,527 114 $ 14,742 $ 15,453 (a) Represents post-modification outstanding recorded investment. (b) Represents pre-modification outstanding recorded investment. Restructured loan modifications may include payment schedule modifications, interest rate concessions, maturity date extensions, modification of note structure (A/B Note), non-reaffirmed Chapter 7 bankruptcies, principal reduction, or some combination of these concessions. During the six months ended June 30, 2016 , restructured loan modifications of commercial and industrial, commercial real estate, and real estate construction loans primarily included maturity date extensions and payment schedule modifications. Restructured loan modifications of home equity and residential mortgage loans primarily included maturity date extensions, interest rate concessions, non-reaffirmed Chapter 7 bankruptcies, or a combination of these concessions for the six months ended June 30, 2016 . The following table provides the number of loans modified in a troubled debt restructuring during the previous twelve months which subsequently defaulted during the six months ended June 30, 2016 and 2015 , as well as the recorded investment in these restructured loans as of June 30, 2016 and 2015 . Six Months Ended June 30, 2016 Six Months Ended June 30, 2015 Number of Loans Recorded Investment Number of Loans Recorded Investment ($ in Thousands) Commercial and industrial — $ — 1 $ 43 Commercial real estate — owner occupied 2 168 1 297 Residential mortgage 25 2,407 29 2,230 Home equity 11 164 22 1,001 Total 38 $ 2,739 53 $ 3,571 All loans modified in a troubled debt restructuring are evaluated for impairment. The nature and extent of the impairment of restructured loans, including those which have experienced a subsequent payment default, is considered in the determination of an appropriate level of the allowance for loan losses. A summary of the changes in the allowance for loan losses by portfolio segment for the six months ended June 30, 2016 , was as follows. $ in Thousands Commercial and industrial Commercial real estate - owner occupied Commercial real estate - investor Real estate construction Residential mortgage Home equity Other consumer Total December 31, 2015 $ 129,959 $ 18,680 $ 43,018 $ 25,266 $ 28,261 $ 23,555 $ 5,525 $ 274,264 Charge offs (37,522 ) (106 ) (887 ) (330 ) (2,334 ) (2,702 ) (1,985 ) (45,866 ) Recoveries 4,022 43 1,566 83 345 1,873 450 8,382 Net charge offs (33,500 ) (63 ) 679 (247 ) (1,989 ) (829 ) (1,535 ) (37,484 ) Provision for loan losses 38,128 (2,767 ) (2,666 ) (3,679 ) 1,624 (1,224 ) 1,584 31,000 June 30, 2016 $ 134,587 $ 15,850 $ 41,031 $ 21,340 $ 27,896 $ 21,502 $ 5,574 $ 267,780 Allowance for loan losses: Individually evaluated for impairment $ — $ 165 $ 45 $ — $ 14 $ — $ — $ 224 Collectively evaluated for impairment 134,587 15,685 40,986 21,340 27,882 21,502 5,574 267,556 Total allowance for loan losses $ 134,587 $ 15,850 $ 41,031 $ 21,340 $ 27,896 $ 21,502 $ 5,574 $ 267,780 Loans: Individually evaluated for impairment $ 191,752 $ 7,790 $ 10,036 $ — $ 6,800 $ 650 $ — $ 217,028 Collectively evaluated for impairment 6,510,234 913,946 3,485,755 1,285,573 6,028,920 968,121 405,709 19,598,258 Total loans $ 6,701,986 $ 921,736 $ 3,495,791 $ 1,285,573 $ 6,035,720 $ 968,771 $ 405,709 $ 19,815,286 The allowance for credit losses is comprised of the allowance for loan losses and the allowance for unfunded commitments. The level of the allowance for loan losses represents management’s estimate of an amount appropriate to provide for probable credit losses in the loan portfolio at the balance sheet date. The allowance for unfunded commitments is maintained at a level believed by management to be sufficient to absorb estimated probable losses related to unfunded credit facilities (including unfunded loan commitments and letters of credit) and is included in accrued expenses and other liabilities on the consolidated balance sheets. See Note 12 for additional information on the allowance for unfunded commitments. For comparison purposes, a summary of the changes in the allowance for loan losses by portfolio segment for the year ended December 31, 2015 , was as follows. $ in Thousands Commercial and industrial Commercial real estate - owner occupied Commercial real estate - investor Real estate construction Residential mortgage Home equity Other consumer Total December 31, 2014 $ 117,635 $ 16,510 $ 46,333 $ 20,999 $ 31,926 $ 26,464 $ 6,435 $ 266,302 Charge offs (27,687 ) (2,645 ) (4,645 ) (750 ) (5,636 ) (7,048 ) (3,869 ) (52,280 ) Recoveries 9,821 921 4,157 2,268 1,077 3,233 765 22,242 Net charge offs (17,866 ) (1,724 ) (488 ) 1,518 (4,559 ) (3,815 ) (3,104 ) (30,038 ) Provision for loan losses 30,190 3,894 (2,827 ) 2,749 894 906 2,194 38,000 December 31, 2015 $ 129,959 $ 18,680 $ 43,018 $ 25,266 $ 28,261 $ 23,555 $ 5,525 $ 274,264 Allowance for loan losses: Individually evaluated for impairment $ 7,522 $ — $ 229 $ — $ 166 $ 46 $ — $ 7,963 Collectively evaluated for impairment 122,437 18,680 42,789 25,266 28,095 23,509 5,525 266,301 Total allowance for loan losses $ 129,959 $ 18,680 $ 43,018 $ 25,266 $ 28,261 $ 23,555 $ 5,525 $ 274,264 Loans: Individually evaluated for impairment $ 91,569 $ 6,221 $ 5,460 $ — $ 6,956 $ 1,281 $ — $ 111,487 Collectively evaluated for impairment 6,099,114 911,991 3,228,806 1,162,145 5,776,311 1,004,521 419,968 18,602,856 Total loans $ 6,190,683 $ 918,212 $ 3,234,266 $ 1,162,145 $ 5,783,267 $ 1,005,802 $ 419,968 $ 18,714,343 A summary of the changes in the allowance for unfunded commitments was as follows. Six Months Ended June 30, 2016 Year Ended December 31, 2015 ($ in Thousands) Allowance for Unfunded Commitments: Balance at beginning of period $ 24,400 $ 24,900 Provision for unfunded commitments 3,000 (500 ) Balance at end of period $ 27,400 $ 24,400 |