XML 82 R52.htm IDEA: XBRL DOCUMENT v3.24.0.1

PENSION PLANS AND POST-RETIREMENT BENEFITS (Tables)

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

Schedule of Net Funded Status

			Pension Benefits																		Post-Retirement Benefits
			Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Change in projected benefit obligation (PBO)			(millions)
PBO as of January 1, 2023			$	1,850.5					$	911.7					$	920.6					$	201.7					$	103.0					$	98.6
Service cost			44.9						18.6						26.3						1.8						0.9						0.9
Interest cost			91.9						47.0						44.0						11.1						5.7						5.5
Contribution by participants			—						—						—						6.2						1.0						5.2
Actuarial (gain) loss			64.8						42.2						22.0						(4.0)						(2.6)						(1.4)
Benefits paid			(84.1)						(50.6)						(32.3)						(24.0)						(10.2)						(13.8)
Settlements			(256.2)						(89.3)						(166.9)						—						—						—
Other			(7.4)						(3.4)						(4.0)						—						—						—
PBO as of December 31, 2023			$	1,704.4					$	876.2					$	809.7					$	192.8					$	97.8					$	95.0
Change in plan assets
Fair value of plan assets as of January 1, 2023			$	1,409.2					$	668.5					$	740.7					$	192.9					$	96.2					$	96.7
Actual return on plan assets			145.2						75.5						69.7						21.6						11.5						10.1
Contributions by employer and participants			36.8						15.1						21.7						9.6						1.2						8.4
Benefits paid			(80.2)						(48.2)						(32.0)						(22.6)						(9.8)						(12.8)
Settlements			(252.9)						(86.9)						(166.0)						—						—						—
Other			(7.4)						(3.4)						(4.0)						—						—						—
Fair value of plan assets as of December 31, 2023			$	1,250.7					$	620.6					$	630.1					$	201.5					$	99.1					$	102.4
Funded status as of December 31, 2023			$	(453.7)					$	(255.6)					$	(179.6)					$	8.7					$	1.3					$	7.4

						Pension Benefits																		Post-Retirement Benefits
						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Change in projected benefit obligation (PBO)						(millions)
PBO as of January 1, 2022						$	2,561.7					$	1,264.4					$	1,273.5					$	258.4					$	133.9					$	124.5
Service cost						79.7						30.7						49.0						3.0						1.5						1.5
Interest cost						79.3						38.8						39.8						7.9						4.1						3.8
Contribution by participants						—						—						—						6.9						1.0						5.8
Plan amendments						0.6						0.3						0.3						—						—						—
Actuarial gain						(717.9)						(334.3)						(378.6)						(58.1)						(28.7)						(29.4)
Benefits paid						(189.4)						(100.1)						(88.0)						(23.1)						(10.2)						(12.9)
Special termination benefits						52.8						15.6						37.2						6.7						1.4						5.3
Other						(16.3)						(3.7)						(12.6)						—						—						—
PBO as of December 31, 2022						$	1,850.5					$	911.7					$	920.6					$	201.7					$	103.0					$	98.6
Change in plan assets
Fair value of plan assets as of January 1, 2022						$	1,714.7					$	835.7					$	879.0					$	242.3					$	124.0					$	118.3
Actual return on plan assets						(192.6)						(97.1)						(95.5)						(34.9)						(19.2)						(15.7)
Contributions by employer and participants						88.4						31.2						57.2						7.0						1.1						5.9
Benefits paid						(185.0)						(97.6)						(87.4)						(21.5)						(9.7)						(11.8)
Other						(16.3)						(3.7)						(12.6)						—						—						—
Fair value of plan assets as of December 31, 2022						$	1,409.2					$	668.5					$	740.7					$	192.9					$	96.2					$	96.7
Funded status as of December 31, 2022						$	(441.3)					$	(243.2)					$	(179.9)					$	(8.8)					$	(6.8)					$	(1.9)

Schedule of Amounts Recognized in Balance Sheet

			Pension Benefits																		Post-Retirement Benefits
			Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Amounts recognized in the consolidated balance sheets															(millions)
Non-current asset			$	—					$	—					$	—					$	24.7					$	5.0					$	19.7
Current pension and other post-retirement liability			(4.5)						(2.5)						(0.5)						(1.1)						(0.5)						(0.6)
Noncurrent pension liability and other post-retirement liability			(449.2)						(253.1)						(179.1)						(14.9)						(3.2)						(11.7)
Net amount recognized before regulatory treatment			(453.7)						(255.6)						(179.6)						8.7						1.3						7.4
Accumulated OCI or regulatory asset/liability			(92.4)						60.7						(144.1)						(34.0)						(18.6)						(21.7)
Net amount recognized as of December 31, 2023			$	(546.1)					$	(194.9)					$	(323.7)					$	(25.3)					$	(17.3)					$	(14.3)
Amounts in accumulated OCI or regulatory asset/liability not yet recognized as a component of net periodic benefit cost:
Actuarial (gain) loss			$	(104.1)					$	47.3					$	(142.8)					$	(34.7)					$	(19.0)					$	(16.9)
Prior service cost			11.7						13.4						(1.3)						0.7						0.4						(4.8)
Net amount recognized as of December 31, 2023			$	(92.4)					$	60.7					$	(144.1)					$	(34.0)					$	(18.6)					$	(21.7)

						Pension Benefits																		Post-Retirement Benefits
						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Amounts recognized in the consolidated balance sheets																		(millions)
Non-current asset						$	—					$	—					$	—					$	16.8					$	—					$	16.8
Current pension and other post-retirement liability						(7.2)						(4.7)						(1.3)						(1.3)						(0.6)						(0.7)
Noncurrent pension liability and other post-    retirement liability						(434.1)						(238.5)						(178.6)						(24.3)						(6.2)						(18.0)
Net amount recognized before regulatory treatment						(441.3)						(243.2)						(179.9)						(8.8)						(6.8)						(1.9)
Accumulated OCI or regulatory asset/liability						(140.2)						50.3						(180.3)						(24.5)						(12.8)						(18.4)
Net amount recognized as of December 31, 2022						$	(581.5)					$	(192.9)					$	(360.2)					$	(33.3)					$	(19.6)					$	(20.3)
Amounts in accumulated OCI or regulatory asset/liability not yet recognized as a component of net periodic benefit cost:
Actuarial (gain) loss						$	(153.8)					$	35.0					$	(179.0)					$	(25.3)					$	(13.2)					$	(13.1)
Prior service cost						13.6						15.3						(1.3)						0.8						0.4						(5.3)
Net amount recognized as of December 31, 2022						$	(140.2)					$	50.3					$	(180.3)					$	(24.5)					$	(12.8)					$	(18.4)

Actuarial losses for the Evergy Companies' pension benefit plans for 2023 were primarily driven by a decrease in the discount rate used to measure the benefit obligation as a result of lower market interest rates. Actuarial gains for the Evergy Companies' pension benefit plans for 2022 were primarily driven by an increase in the discount rate used to measure the benefit obligation as a result of higher market interest rates. See the weighted average assumptions used to determine the benefit obligations within this Note 9 for further information.

Schedule of Net Benefit Costs

The assets in the aforementioned trusts are not included in the table above. See Note 14 for more information on these amounts.

						Pension Benefits																		Post-Retirement Benefits
Year Ended December 31, 2023						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Components of net periodic benefit costs						(millions)
Service cost						$	44.9					$	18.6					$	26.3					$	1.8					$	0.9					$	0.9
Interest cost						91.9						47.0						44.0						11.1						5.7						5.5
Expected return on plan assets						(87.6)						(44.1)						(43.4)						(11.9)						(6.3)						(5.7)
Prior service cost						1.9						2.0						—						0.1						—						(0.4)
Recognized net actuarial (gain) loss						(21.5)						(2.5)						(18.2)						(4.2)						(2.0)						(2.1)
Settlement and special termination (gain) loss						(21.1)						1.1						(22.2)						—						—						—
Net periodic benefit costs before regulatory adjustment and intercompany allocations						8.5						22.1						(13.5)						(3.1)						(1.7)						(1.8)
Regulatory adjustment						94.0						30.4						63.0						(0.1)						(1.7)						2.1
Intercompany allocations						n/a						(2.3)						(1.1)						n/a						0.3						—
Net periodic benefit costs (income)						102.5						50.2						48.4						(3.2)						(3.1)						0.3
Other changes in plan assets and benefit obligations recognized in OCI or regulatory assets/liabilities
Current year net (gain) loss						7.1						11.0						(4.2)						(13.6)						(7.8)						(5.8)
Amortization of gain						21.5						2.5						18.2						4.2						2.0						2.1
Amortization of prior service cost						(1.9)						(2.0)						—						(0.1)						—						0.4
Net gain (loss) due to settlement						21.1						(1.1)						22.2						—						—						—
Total recognized in OCI or regulatory asset/liability						47.8						10.4						36.2						(9.5)						(5.8)						(3.3)
Total recognized in net periodic benefit costs and OCI or regulatory asset/liability						$	150.3					$	60.6					$	84.6					$	(12.7)					$	(8.9)					$	(3.0)

						Pension Benefits																		Post-Retirement Benefits
Year Ended December 31, 2022						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Components of net periodic benefit costs						(millions)
Service cost						$	79.7					$	30.7					$	49.0					$	3.0					$	1.5					$	1.5
Interest cost						79.3						38.8						39.8						7.9						4.1						3.8
Expected return on plan assets						(104.0)						(51.2)						(56.4)						(10.2)						(6.5)						(3.7)
Prior service cost						1.9						2.0						—						0.5						0.4						(1.4)
Recognized net actuarial (gain) loss						34.8						25.6						38.6						(0.3)						(0.2)						(0.7)
Settlement and special termination benefits						52.8						15.6						37.2						6.7						1.4						5.3
Net periodic benefit costs before regulatory adjustment and intercompany allocations						144.5						61.5						108.2						7.6						0.7						4.8
Regulatory adjustment						14.7						0.7						(12.1)						(7.1)						(3.6)						(1.3)
Intercompany allocations						n/a						2.9						(18.4)						n/a						0.3						(0.6)
Net periodic benefit costs (income)						159.2						65.1						77.7						0.5						(2.6)						2.9
Other changes in plan assets and benefit obligations recognized in OCI or regulatory assets/liabilities
Current year net gain						(421.4)						(186.1)						(226.7)						(13.0)						(3.0)						(10.0)
Amortization of gain (loss)						(34.7)						(25.6)						(38.6)						0.4						0.2						0.7
Prior service cost						0.6						0.4						0.4						—						—						—
Amortization of prior service cost						(1.9)						(2.0)						—						(0.5)						(0.4)						1.4
Total recognized in OCI or regulatory asset/liability						(457.4)						(213.3)						(264.9)						(13.1)						(3.2)						(7.9)
Total recognized in net periodic benefit costs and OCI or regulatory asset/liability						$	(298.2)					$	(148.2)					$	(187.2)					$	(12.6)					$	(5.8)					$	(5.0)

						Pension Benefits																		Post-Retirement Benefits
Year Ended December 31, 2021						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Components of net periodic benefit costs						(millions)
Service cost						$	82.6					$	29.1					$	53.5					$	3.3					$	1.7					$	1.6
Interest cost						84.2						41.0						42.5						7.8						4.0						3.8
Expected return on plan assets						(103.5)						(52.8)						(55.7)						(8.9)						(6.3)						(2.6)
Prior service cost						2.0						2.1						—						0.5						0.5						(1.0)
Recognized net actuarial loss						54.1						36.0						43.8						1.4						0.6						(0.1)
Settlement and special termination benefits						34.3						25.6						13.7						—						—						—
Net periodic benefit costs before regulatory adjustment and intercompany allocations						153.7						81.0						97.8						4.1						0.5						1.7
Regulatory adjustment						17.3						(13.1)						4.2						(4.8)						(3.3)						0.4
Intercompany allocations						n/a						3.2						(25.9)						n/a						—						(0.4)
Net periodic benefit costs (income)						171.0						71.1						76.1						(0.7)						(2.8)						1.7
Other changes in plan assets and benefit obligations recognized in OCI or regulatory assets/liabilities
Current year net gain						(195.3)						(106.3)						(88.4)						(13.6)						(9.6)						(3.9)
Amortization of gain (loss)						(52.4)						(36.0)						(43.9)						(1.3)						(0.5)						0.1
Amortization of prior service cost						(2.0)						(2.1)						—						(0.5)						(0.5)						1.0
Total recognized in OCI or regulatory asset/liability						(249.7)						(144.4)						(132.3)						(15.4)						(10.6)						(2.8)
Total recognized in net periodic benefit costs and OCI or regulatory asset/liability						$	(78.7)					$	(73.3)					$	(56.2)					$	(16.1)					$	(13.4)					$	(1.1)

Schedule of Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets

Pension and other post-retirement benefit plans with the PBO, accumulated benefit obligation (ABO) or accumulated other post-retirement benefit obligation (APBO) in excess of the fair value of plan assets at year-end are detailed in the following tables.

December 31, 2023						Evergy						Evergy Kansas Central						Evergy Metro
						(millions)
ABO for all defined benefit pension plans						$	1,539.7					$	809.9					$	711.3
Pension plans with the PBO in excess of plan assets
Projected benefit obligation						$	1,704.4					$	876.2					$	809.7
Fair value of plan assets						1,250.7						620.6						630.1
Pension plans with the ABO in excess of plan assets
Accumulated benefit obligation						$	1,539.7					$	809.9					$	711.3
Fair value of plan assets						1,250.7						620.6						630.1
Other post-retirement benefit plans with the APBO in excess of plan assets
Accumulated other post-retirement benefit obligation						$	82.6					$	3.5					$	79.1
Fair value of plan assets						66.9						—						66.9

December 31, 2022						Evergy						Evergy Kansas Central						Evergy Metro
						(millions)
ABO for all defined benefit pension plans						$	1,687.3					$	844.4					$	824.6
Pension plans with the PBO in excess of plan assets
Projected benefit obligation						$	1,850.5					$	911.7					$	920.6
Fair value of plan assets						1,409.2						668.5						740.7
Pension plans with the ABO in excess of plan assets
Accumulated benefit obligation						$	1,687.3					$	844.4					$	824.6
Fair value of plan assets						1,409.2						668.5						740.7
Other post-retirement benefit plans with the APBO in excess of plan assets
Accumulated other post-retirement benefit obligation						$	201.7					$	103.0					$	98.6
Fair value of plan assets						192.9						96.2						96.7

Schedule of Defined Benefit Plan, Assumptions

The following tables provide the weighted-average assumptions used to determine benefit obligations and net costs for the Evergy Companies' pension and post-retirement benefit plans.

Weighted-average assumptions used to determine the benefit obligation at December 31, 2023						Pension Benefits																		Post-Retirement Benefits
						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Discount rate						5.35		%				5.34		%				5.35		%				5.43		%				5.45		%				5.41		%
Rate of compensation increase						3.72		%				3.77		%				3.71		%				3.75		%				n/a						3.75		%
Interest crediting rate for cash balance plans						4.13		%				4.20		%				4.47		%				n/a						n/a						n/a
Weighted-average assumptions used to determine the benefit obligation at December 31, 2022						Pension Benefits																		Post-Retirement Benefits
						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Discount rate						5.72		%				5.72		%				5.72		%				5.74		%				5.75		%				5.72		%
Rate of compensation increase						3.72		%				3.78		%				3.70		%				3.75		%				n/a						3.75		%
Interest crediting rate for cash balance plans						4.13		%				4.00		%				4.43		%				n/a						n/a						n/a

Weighted-average assumptions used to determine net costs for the year ended December 31, 2023						Pension Benefits																		Post-Retirement Benefits
						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Discount rate						5.45		%				5.66		%				5.62		%				5.74		%				5.75		%				5.72		%
Expected long-term return on plan assets						6.71		%				6.80		%				6.62		%				5.48		%				5.75		%				5.22		%
Rate of compensation increase						3.72		%				3.78		%				3.70		%				3.75		%				n/a						3.75		%
Interest crediting rate for cash balance plans						4.13		%				4.00		%				4.43		%				n/a						n/a						n/a
Weighted-average assumptions used to determine net costs for the year ended December 31, 2022						Pension Benefits																		Post-Retirement Benefits
						Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
Discount rate						3.10		%				3.10		%				3.11		%				3.12		%				3.11		%				3.13		%
Expected long-term return on plan assets						6.71		%				6.80		%				6.63		%				4.53		%				5.75		%				3.25		%
Rate of compensation increase						3.75		%				3.77		%				3.71		%				3.75		%				n/a						3.75		%
Interest crediting rate for cash balance plans						4.13		%				4.00		%				4.45		%				n/a						n/a						n/a

Schedule of Expected Benefit Payments

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid through 2033.

			Pension Benefits																		Post-Retirement Benefits
			Evergy						Evergy Kansas Central						Evergy Metro						Evergy						Evergy Kansas Central						Evergy Metro
			(millions)
2024			$	135.6					$	74.4					$	59.6					$	18.2					$	10.3					$	7.8
2025			136.5						73.5						61.4						17.6						9.9						7.8
2026			138.9						72.9						64.4						17.1						9.4						7.7
2027			140.4						72.4						66.5						15.2						8.2						7.0
2028			141.1						71.5						68.1						14.4						7.8						6.6
2029-2033			707.7						344.0						356.5						66.3						35.0						31.3

Schedule of Allocation of Plan Assets

The following table provides the target asset allocations by asset class for the Evergy Kansas Central and Evergy Metro pension and other post-retirement plan assets.

			Pension Benefits												Post-Retirement Benefits
			Evergy Kansas Central						Evergy Metro						Evergy Kansas Central						Evergy Metro
Domestic equities			26%						26%						26%						18%
International equities			20%						19%						18%						10%
Bonds			39%						38%						56%						66%
Mortgage & asset backed securities			—%						—%						—%						5%
Real estate investments			4%						6%						—%						—%
Other investments			11%						11%						—%						1%

The fair values of the Evergy Companies' pension plan assets at December 31, 2023 and 2022, by asset category are in the following tables.

												Fair Value Measurements Using
Description			December 31 2023									Level 1												Level 2												Level 3												Assets measured at NAV
Evergy Kansas Central Pension Plans						(millions)
Domestic equities						$	145.9								$	124.0											$	—											$	—											$	21.9
International equities						118.2									118.2												—												—												—
Bond funds						224.2									224.2												—												—												—
Real estate investments						23.0									—												—												—												23.0
Combination debt/equity/other fund						29.2									29.2												—												—												—
Alternative investment funds						74.6									—												—												—												74.6
Short-term investments						5.5									—												—												—												5.5
Total						$	620.6								$	495.6											$	—											$	—											$	125.0
Evergy Metro Pension Plans
Domestic equities						$	138.9								$	122.9											$	—											$	—											$	16.0
International equities						120.0									120.0												—												—												—
Bond funds						174.9									174.9												—												—												—
Corporate bonds						21.1									—												21.1												—												—
U.S. Treasury and agency bonds						10.1									5.1												5.0												—												—
Mortgage and asset backed securities						5.1									—												5.1												—												—
Real estate investments						49.0									—												—												—												49.0
Combination debt/equity/other fund						28.4									28.4												—												—												—
Alternative investment funds						70.8									—												—												—												70.8
Cash and cash equivalents						5.9									5.9												—												—												—
Short-term investments						4.0									—												—												—												4.0
Other						1.9									—												1.9												—												—
Total						$	630.1								$	457.2											$	33.1											$	—											$	139.8

												Fair Value Measurements Using
Description			December 31 2022									Level 1												Level 2												Level 3												Assets measured at NAV
Evergy Kansas Central Pension Plans						(millions)
Domestic equities						$	156.8								$	129.2											$	—											$	—											$	27.6
International equities						129.1									129.1												—												—												—
Bond funds						241.7									241.7												—												—												—
Real estate investments						26.8									—												—												—												26.8
Combination debt/equity/other fund						30.8									30.8												—												—												—
Alternative investment funds						63.9									—												—												—												63.9
Short-term investments						19.4									—												—												—												19.4
Total						$	668.5								$	530.8											$	—											$	—											$	137.7
Evergy Metro Pension Plans
Domestic equities						$	156.1								$	135.5											$	—											$	—											$	20.6
International equities						136.7									136.7												—												—												—
Bond funds						195.2									195.2												—												—												—
Corporate bonds						23.7									—												23.7												—												—
U.S. Treasury and agency bonds						14.0									5.8												8.2												—												—
Mortgage and asset backed securities						5.0									—												5.0												—												—
Real estate investments						59.0									—												—												—												59.0
Combination debt/equity/other fund						31.2									31.2												—												—												—
Alternative investment funds						63.1									—												—												—												63.1
Cash and cash equivalents						44.6									44.6												—												—												—
Short-term investments						14.6									—												—												—												14.6
Other						(2.5)									—												(2.5)												—												—
Total						$	740.7								$	549.0											$	34.4											$	—											$	157.3

The fair values of the Evergy Companies' post-retirement plan assets at December 31, 2023 and 2022, by asset category are in the following tables.

												Fair Value Measurements Using
Description			December 31 2023									Level 1												Level 2												Level 3												Assets measured at NAV
Evergy Kansas Central Post-Retirement Benefit Plans						(millions)
Domestic equities						$	26.1								$	26.1											$	—											$	—											$	—
International equities						17.9									17.9												—												—												—
Bond funds						49.6									49.6												—												—												—
Combination debt/equity/other fund						4.5									4.5												—												—												—
Short-term investments						1.0									—												—												—												1.0
Total						$	99.1								$	98.1											$	—											$	—											$	1.0
Evergy Metro Post-Retirement Benefit Plans
Domestic equities						$	21.8								$	21.8											$	—											$	—											$	—
International equities						12.1									12.1												—												—												—
Bond funds						36.8									36.8												—												—												—
Corporate bonds						15.0									—												15.0												—												—
U.S. Treasury and agency bonds						12.2									6.1												6.1												—												—
Mortgage and asset backed securities						1.0									—												1.0												—												—
Combination debt/equity/other fund						3.0									3.0												—												—												—
Short-term investments						0.2									—												—												—												0.2
Other						0.3									—												0.3												—												—
Total						$	102.4								$	79.8											$	22.4											$	—											$	0.2

												Fair Value Measurements Using
Description			December 31 2022									Level 1												Level 2												Level 3												Assets measured at NAV
Evergy Kansas Central Post-Retirement Benefit Plans						(millions)
Domestic equities						$	24.2								$	24.2											$	—											$	—											$	—
International equities						17.5									17.5												—												—												—
Bond funds						48.7									48.7												—												—												—
Combination debt/equity/other fund						4.8									4.8												—												—												—
Short-term investments						1.0									—												—												—												1.0
Total						$	96.2								$	95.2											$	—											$	—											$	1.0
Evergy Metro Post-Retirement Benefit Plans
Domestic equities						$	18.7								$	18.7											$	—											$	—											$	—
International equities						11.6									11.6												—												—												—
Bond funds						34.9									34.9												—												—												—
Corporate bonds						14.6									—												14.6												—												—
U.S. Treasury and agency bonds						12.3									6.0												6.3												—												—
Mortgage and asset backed securities						1.3									—												1.3												—												—
Combination debt/equity/other fund						2.9									2.9												—												—												—
Cash and cash equivalents						0.2									0.2												—												—												—
Other						0.2									—												0.2												—												—
Total						$	96.7								$	74.3											$	22.4											$	—											$	—

Schedule of Health Care Cost Trend Rates

The cost trend assumptions are detailed in the following tables.

Assumed annual health care cost growth rates as of December 31, 2023						Evergy						Evergy Kansas Central						Evergy Metro
Health care cost trend rate assumed for next year						6.9		%				6.9		%				6.9		%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)						4.5		%				4.5		%				4.5		%
Year that rate reaches ultimate trend						2030						2030						2030
Assumed annual health care cost growth rates as of December 31, 2022						Evergy						Evergy Kansas Central						Evergy Metro
Health care cost trend rate assumed for next year						7.3		%				7.3		%				7.3		%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)						4.5		%				4.5		%				4.5		%
Year that rate reaches ultimate trend						2030						2030						2030

Schedule of Costs of Retirement Plans

Evergy has defined contribution savings plans (401(k)) that cover substantially all employees. Evergy matches employee contributions, subject to limits. The annual costs of the plans are detailed in the following table.

						2023						2022						2021
						(millions)
Evergy						$	24.1					$	25.3					$	25.6
Evergy Kansas Central						11.3						12.0						11.7
Evergy Metro						12.8						13.3						13.9

X

- References

No definition available.

+ Details

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (d)(5)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of assumption used to determine benefit obligation and net periodic benefit cost of defined benefit plan. Includes, but is not limited to, discount rate, rate of compensation increase, expected long-term rate of return on plan assets and interest crediting rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAssumptionsUsedTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of benefit obligation and plan assets for defined benefit pension plan with projected benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480482/715-20-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-3

+ Details

Name:	us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the costs related to the various types of retirement plans including defined benefit pension plan cost, defined contribution plan cost, other postretirement benefit plan cost, and net periodic benefit cost.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-SubTopic 20
-Topic 715
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfCostsOfRetirementPlansTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (f)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the assumed health care cost trend rates for the next year used to measure the expected cost of benefits covered by the plans, including the ultimate trend rate(s) and when that rate is expected to be achieved.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (l)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfHealthCareCostTrendRatesTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (h)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of net funded status of pension plans and/or other employee benefit plans.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfNetFundedStatusTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration