| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | A. O. Smith Corporation |
| Entity Central Index Key | 0000091142 |
| Pay vs Performance Disclosure Unit_pure in Millions | 12 Months Ended | ||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | |
| Pay vs Performance Disclosure [Table] | |||
| Pay vs Performance [Table Text Block] | PAY VERSUS PERFORMANCE DISCLOSURE In accordance with SEC rules, we prepared the analysis set forth below of the relationship between the compensation actually paid to our CEO and other named executive officers, and certain financial performance measures over the last three fiscal years. Pay versus Performance Disclosure Table Value of Initial Fixed $100 Year Summary 1 Compensation 2 Average Non-CEO NEOs 3 Average Non-CEO NEOs ($) 4 Total Peer Group 5 Net Income Earnings 6 2022 $ 6,640,047 $ 180,882 $ 1,691,156 $ 577,901 $ 127 $ 125 $ 236 $ 233 2021 6,897,982 14,651,874 2,094,815 3,447,584 187 152 487 630 2020 5,174,751 6,941,943 2,558,990 2,825,096 117 118 345 451 1 The dollar amounts reported in this column are the amounts of total compensation reported for Mr. Wheeler, our chairman, president and chief executive officer for each corresponding year in the “Total” column of the Summary Compensation Table (“SCT”). 2 The dollar amounts reported in this column represent the amount of “Compensation Actually Paid” to Mr. Wheeler as computed in accordance with Item 402(v) of Regulation S-K. S-K, Adjustments to Determine Compensation Actually Paid for CEO 2022 2021 2020 Deduction for Change in the Actuarial Present Values reported under the “Change in Pension Value and Non-qualified Deferred Compensation Earnings” Column of the SCT $ (42,393 ) $ — $ (142,120 ) Increase for “Service Cost” for Pension Plans — — — Deduction for Amounts Reported under the “Stock Awards” Column in the SCT (1,517,977 ) (1,386,088 ) (1,320,025 ) Deduction for Amounts Reported under the “Option Awards” Column in the SCT (1,518,003 ) (1,385,968 ) (1,320,016 ) Increase for Fair Value of Awards Granted during year that Remain Unvested as of Year End 2,142,436 4,852,502 4,189,162 Increase/deduction for Change in Fair Value from prior Year End to current Year End of Awards Granted Prior to year that were Outstanding and Unvested as of Year end (3,958,480 ) 5,115,965 439,083 Increase/deduction for Change in Fair Value from Prior Year End to Vesting Date of Awards Granted Prior to year that Vested during year (1,564,747 ) 557,481 (78,893 ) Total Adjustments $ (6,459,164 ) $ 7,753,892 $ 1,767,191 3 The dollar amounts reported in this column represent the average of the amounts reported for the company’s named executive officers as a group (excluding Mr. Wheeler) in the “Total” column of the Summary Compensation Table in each applicable year. The names of each of the named executive officers (excluding Mr. Wheeler) included for purposes of calculating the average amounts in each applicable year are as follows: (i) for 2022, Messrs. Lauber, Stern, Petrarca, and Warren; (ii) for 2021, Messrs. Lauber, Stern, Petrarca, and Warren; and (iii) for 2020, Messrs. Lauber, Stern, Petrarca, Warren, and Rajendra. 4 The dollar amounts reported in this column represent the average amount of “compensation actually paid” to the named executive officers as a group (excluding Mr. Wheeler), as computed in accordance with Item 402(v) of Regulation S-K. S-K, Adjustments to Determine Compensation Actually Paid for Non-CEO 2022 2021 2020 Deduction for Change in the Actuarial Present Values reported under the “Change in Pension Value and Non-qualified Deferred Compensation Earnings” Column of the SCT — $ (206,124 ) $ (513,175 ) Increase for “Service Cost” for Pension Plans 103,701 107,498 117,666 Deduction for Amounts Reported under the “Stock Awards” Column in the SCT (283,785 ) (260,766 ) (432,802 ) Deduction for Amounts Reported under the “Option Awards” Column in the SCT (283,812 ) (260,710 ) (432,818 ) Increase for Fair Value of Awards Granted during year that Remain Unvested as of Year End 387,072 912,834 1,373,554 Increase/deduction for Change in Fair Value from prior Year End to current Year End of Awards Granted Prior to year that were Outstanding and Unvested as of Year End (711,758 ) 961,004 220,982 Increase/deduction for Change in Fair Value from Prior Year-End (324,673 ) 99,032 (67,301 ) Total Adjustments $ (1,113,255 ) $ 1,352,768 $ 266,106 5 The peer group used for this purpose is the S&P Industrials Index. 6 We have determined that EBIT is the financial performance measure that, in our assessment, represents the most important performance measure (that is not otherwise required to be disclosed in the table) used to link compensation actually paid to our named executive officers, for the most recently completed fiscal year, to company performance. | ||
| Company Selected Measure Name | Earningsbefore Interestand Taxes | ||
| Named Executive Officers, Footnote [Text Block] | The names of each of the named executive officers (excluding Mr. Wheeler) included for purposes of calculating the average amounts in each applicable year are as follows: (i) for 2022, Messrs. Lauber, Stern, Petrarca, and Warren; (ii) for 2021, Messrs. Lauber, Stern, Petrarca, and Warren; and (iii) for 2020, Messrs. Lauber, Stern, Petrarca, Warren, and Rajendra. | ||
| Peer Group Issuers, Footnote [Text Block] | The peer group used for this purpose is the S&P Industrials Index. | ||
| PEO Total Compensation Amount | $ 6,640,047 | $ 6,897,982 | $ 5,174,751 |
| PEO Actually Paid Compensation Amount | $ 180,882 | 14,651,874 | 6,941,943 |
| Adjustment To PEO Compensation, Footnote [Text Block] | 2 The dollar amounts reported in this column represent the amount of “Compensation Actually Paid” to Mr. Wheeler as computed in accordance with Item 402(v) of Regulation S-K. S-K, Adjustments to Determine Compensation Actually Paid for CEO 2022 2021 2020 Deduction for Change in the Actuarial Present Values reported under the “Change in Pension Value and Non-qualified Deferred Compensation Earnings” Column of the SCT $ (42,393 ) $ — $ (142,120 ) Increase for “Service Cost” for Pension Plans — — — Deduction for Amounts Reported under the “Stock Awards” Column in the SCT (1,517,977 ) (1,386,088 ) (1,320,025 ) Deduction for Amounts Reported under the “Option Awards” Column in the SCT (1,518,003 ) (1,385,968 ) (1,320,016 ) Increase for Fair Value of Awards Granted during year that Remain Unvested as of Year End 2,142,436 4,852,502 4,189,162 Increase/deduction for Change in Fair Value from prior Year End to current Year End of Awards Granted Prior to year that were Outstanding and Unvested as of Year end (3,958,480 ) 5,115,965 439,083 Increase/deduction for Change in Fair Value from Prior Year End to Vesting Date of Awards Granted Prior to year that Vested during year (1,564,747 ) 557,481 (78,893 ) Total Adjustments $ (6,459,164 ) $ 7,753,892 $ 1,767,191 | ||
| Non-PEO NEO Average Total Compensation Amount | $ 1,691,156 | 2,094,815 | 2,558,990 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 577,901 | 3,447,584 | 2,825,096 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | 4 The dollar amounts reported in this column represent the average amount of “compensation actually paid” to the named executive officers as a group (excluding Mr. Wheeler), as computed in accordance with Item 402(v) of Regulation S-K. S-K, Adjustments to Determine Compensation Actually Paid for Non-CEO 2022 2021 2020 Deduction for Change in the Actuarial Present Values reported under the “Change in Pension Value and Non-qualified Deferred Compensation Earnings” Column of the SCT — $ (206,124 ) $ (513,175 ) Increase for “Service Cost” for Pension Plans 103,701 107,498 117,666 Deduction for Amounts Reported under the “Stock Awards” Column in the SCT (283,785 ) (260,766 ) (432,802 ) Deduction for Amounts Reported under the “Option Awards” Column in the SCT (283,812 ) (260,710 ) (432,818 ) Increase for Fair Value of Awards Granted during year that Remain Unvested as of Year End 387,072 912,834 1,373,554 Increase/deduction for Change in Fair Value from prior Year End to current Year End of Awards Granted Prior to year that were Outstanding and Unvested as of Year End (711,758 ) 961,004 220,982 Increase/deduction for Change in Fair Value from Prior Year-End (324,673 ) 99,032 (67,301 ) Total Adjustments $ (1,113,255 ) $ 1,352,768 $ 266,106 | ||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | The following chart provides a graphical representation of the Compensation Actually Paid to our CEO and other named executive officers versus the company’s three-year | ||
| Compensation Actually Paid vs. Net Income [Text Block] | The following chart provides a graphical representation of the Compensation Actually Paid to our CEO and other named executive officers versus the company’s Net Income. | ||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | The following chart provides a graphical representation of the Compensation Actually Paid to our CEO and other named executive officers versus the company’s selected measure, EBIT. | ||
| Total Shareholder Return Vs Peer Group [Text Block] | The following chart provides a graphical representation of the company’s three-year The following chart provides a graphical representation of the Compensation Actually Paid to our CEO and other named executive officers versus the peer group (S&P Industrials Index) three-year | ||
| Tabular List [Table Text Block] | Most Important Performance Measures Earnings before Interest and Taxes (EBIT) Return on Invested Capital (ROIC) Net Sales Return on Equity Return on Performance Assets (business unit) Performance Earnings before Interest and Taxes (PEBIT) | ||
| Total Shareholder Return Amount | $ 127 | 187 | 117 |
| Peer Group Total Shareholder Return Amount | 125 | 152 | 118 |
| Net Income (Loss) | $ 236,000,000 | $ 487,000,000 | $ 345,000,000 |
| Company Selected Measure Amount | 233 | 630 | 451 |
| PEO Name | Mr. Wheeler | ||
| Value of Initial Fixed Investment | $ 100 | ||
| Measure [Axis]: 1 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Earnings before Interest and Taxes (EBIT) | ||
| Non-GAAP Measure Description [Text Block] | We have determined that EBIT is the financial performance measure that, in our assessment, represents the most important performance measure (that is not otherwise required to be disclosed in the table) used to link compensation actually paid to our named executive officers, for the most recently completed fiscal year, to company performance. | ||
| Measure [Axis]: 2 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Return on Invested Capital (ROIC) | ||
| Measure [Axis]: 3 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Net Sales | ||
| Measure [Axis]: 4 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Return on Equity | ||
| Measure [Axis]: 5 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Return on Performance Assets (business unit) | ||
| Measure [Axis]: 6 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Performance Earnings before Interest and Taxes (PEBIT) | ||
| PEO [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ (6,459,164) | $ 7,753,892 | $ 1,767,191 |
| PEO [Member] | Deduction for Change in the Actuarial Present Values reported under the "Change in Pension Value and Non-qualified Deferred Compensation Earnings" Column of the SCT [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (42,393) | (142,120) | |
| PEO [Member] | Deduction for Amounts Reported under the "Stock Awards" Column in the SCT [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (1,517,977) | (1,386,088) | (1,320,025) |
| PEO [Member] | Deduction for Amounts Reported under the "Option Awards" Column in the SCT [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (1,518,003) | (1,385,968) | (1,320,016) |
| PEO [Member] | Increase for Fair Value of Awards Granted during year that Remain Unvested as of Year End [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 2,142,436 | 4,852,502 | 4,189,162 |
| PEO [Member] | Increase/deduction for Change in Fair Value from prior Year End to current Year End of Awards Granted Prior to year that were Outstanding and Unvested as of Year end [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (3,958,480) | 5,115,965 | 439,083 |
| PEO [Member] | Increase/deduction for Change in Fair Value from Prior Year End to Vesting Date of Awards Granted Prior to year that Vested during year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (1,564,747) | 557,481 | (78,893) |
| Non-PEO NEO [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (1,113,255) | 1,352,768 | 266,106 |
| Non-PEO NEO [Member] | Deduction for Change in the Actuarial Present Values reported under the "Change in Pension Value and Non-qualified Deferred Compensation Earnings" Column of the SCT [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (206,124) | (513,175) | |
| Non-PEO NEO [Member] | Increase for "Service Cost" for Pension Plans [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 103,701 | 107,498 | 117,666 |
| Non-PEO NEO [Member] | Deduction for Amounts Reported under the "Stock Awards" Column in the SCT [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (283,785) | (260,766) | (432,802) |
| Non-PEO NEO [Member] | Deduction for Amounts Reported under the "Option Awards" Column in the SCT [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (283,812) | (260,710) | (432,818) |
| Non-PEO NEO [Member] | Increase for Fair Value of Awards Granted during year that Remain Unvested as of Year End [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | 387,072 | 912,834 | 1,373,554 |
| Non-PEO NEO [Member] | Increase/deduction for Change in Fair Value from prior Year End to current Year End of Awards Granted Prior to year that were Outstanding and Unvested as of Year end [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | (711,758) | 961,004 | 220,982 |
| Non-PEO NEO [Member] | Increase/deduction for Change in Fair Value from Prior Year End to Vesting Date of Awards Granted Prior to year that Vested during year [Member] | |||
| Pay vs Performance Disclosure [Table] | |||
| Adjustment to Compensation Amount | $ (324,673) | $ 99,032 | $ (67,301) |
