| Plan sponsor | ATC MANAGEMENT INC | Form 5500, Part II line 2a; SPONSOR_DFE_NAME pos 19; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Plan name | ATC 401(K) PLAN | Form 5500, line 1a; PLAN_NAME pos 16; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Sponsor EIN / plan number | 39-1999363 / 001 | Form 5500, line 2b; SPONS_DFE_EIN pos 44; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Plan type | single-employer | Form 5500, Part I line A; TYPE_PLAN_ENTITY_CD pos 4; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Sponsor location | WAUKESHA, WI | Form 5500, line 2a; SPONS_DFE_MAIL_US_STATE pos 25; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Industry (business code) | 221100, Utilities | Form 5500, line 2d; BUSINESS_CODE pos 46; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Plan year | 2024-01-01 to 2024-12-31 | Form 5500, Part I plan year; FORM_PLAN_YEAR_BEGIN_DATE pos 2; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Filing received | 2025-09-29 | Form 5500, EFAST2 receipt date; DATE_RECEIVED pos 102; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Final filing | no | Form 5500, Part I line B; FINAL_FILING_IND pos 8; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Amended filing | no | Form 5500, Part I line B; AMENDED_IND pos 7; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Participants, beginning of year | 659 | Form 5500, line 5; TOT_PARTCP_BOY_CNT pos 71; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Active participants | 587 | Form 5500, line 6a(2); TOT_ACTIVE_PARTCP_CNT pos 72; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Participants, end of year | 715 | Form 5500, line 6f; TOT_ACT_RTD_SEP_BENEF_CNT pos 77; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Participants with an account balance | 686 | Form 5500, line 6g(2); PARTCP_ACCOUNT_BAL_CNT pos 78; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Total assets, beginning of year | $179,949,884 | Schedule H, Part I line 1f col (a); TOT_ASSETS_BOY_AMT pos 30; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Total assets, end of year | $206,395,221 | Schedule H, Part I line 1f col (b); TOT_ASSETS_EOY_AMT pos 61; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Net assets, end of year | $206,395,221 | Schedule H, line 1l col (b); NET_ASSETS_EOY_AMT pos 67; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Total income | $39,669,105 | Schedule H, Part II line 2d; TOT_INCOME_AMT pos 97; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Net income | $26,445,337 | Schedule H, line 2k; NET_INCOME_AMT pos 111; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Employer contributions | $3,190,893 | Schedule H, Part II line 2a(1)(A); EMPLR_CONTRIB_INCOME_AMT pos 68; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Participant contributions | $8,582,893 | Schedule H, line 2a(1)(B); PARTICIPANT_CONTRIB_AMT pos 69; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Other contributions (incl. rollovers) | $1,376,129 | Schedule H, line 2a(1)(C); OTH_CONTRIB_RCVD_AMT pos 70; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Total contributions | $13,149,915 | Schedule H, line 2a(3); TOT_CONTRIB_AMT pos 72; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Benefit payments | $13,078,470 | Schedule H, line 2e(4); TOT_DISTRIB_BNFT_AMT pos 101; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Total expenses (incl. benefit payments) | $13,223,768 | Schedule H, line 2j; TOT_EXPENSES_AMT pos 110; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Total administrative expenses | $145,298 | Schedule H, line 2i(12) total administrative expenses; TOT_ADMIN_EXPENSES_AMT pos 109; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Contract administrator fees | $0 | Schedule H, line 2i(2); CONTRACT_ADMIN_FEES_AMT pos 106; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Recordkeeping fees | $33,716 | Schedule H, line 2i(3); OTH_RECORDKEEPING_FEES_AMT pos 160; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| IQPA audit fees | $18,000 | Schedule H, line 2i(4); IQPA_AUDIT_FEES_AMT pos 161; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Investment advisory and management fees | $93,582 | Schedule H, line 2i(5); INVST_MGMT_FEES_AMT pos 107; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Administrative expenses excluding investment management | $51,716 | derived, admin_expenses (2i(12)) minus invst_mgmt_fees (2i(5)), floored at 0; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Held in master trusts | $0 | Schedule H, line 1c(11) col (b); INT_MASTER_TR_EOY_AMT pos 53; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Held in common/collective trusts | $13,835,519 | Schedule H, line 1c(9) col (b); INT_COMMON_TR_EOY_AMT pos 51; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Held in mutual funds | $177,944,923 | Schedule H, line 1c(13) col (b); INT_REG_INVST_CO_EOY_AMT pos 55; filing 20250929143419NAL0015337747001, received 2025-09-29 |
| Independent auditor | COLEMAN & WILLIAMS LTD | Schedule H, Part III line 3a; ACCOUNTANT_FIRM_NAME pos 116; filing 20250929143419NAL0015337747001, received 2025-09-29 |