v3.26.1
Fair Value Measurements - Schedule of Investments Excluding Master Trust (Details) - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value $ 145,491,699 $ 130,639,630
Total investments 29,625,703 29,163,338
EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 1,722,095,678 1,518,575,810
Total investments 282,008,750 273,390,578
Investment, payable from master trust   1,227,294
Total | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 448,512 417,504
Total investments 29,436,155 29,081,111
Total | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 2,172,325 3,223,546
Total investments 279,863,679 272,498,902
Total | Common stock | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 10,638,503 11,463,952
Total | Common stock | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 120,393,665 124,314,999
Total | Mutual funds | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 448,512 417,504
Total investments 11,230,387 11,145,222
Total | Mutual funds | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 2,172,325 3,223,546
Total investments 127,091,890 120,858,693
Total | Brunswick ESOP Company Stock Fund | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 7,567,265 6,471,937
Total | Brunswick ESOP Company Stock Fund | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 32,378,124 27,325,210
Level 1 | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 448,512 417,504
Total investments 29,436,155 29,081,111
Level 1 | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 2,172,325 3,223,546
Total investments 279,863,679 272,498,902
Level 1 | Common stock | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 10,638,503 11,463,952
Level 1 | Common stock | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 120,393,665 124,314,999
Level 1 | Mutual funds | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 448,512 417,504
Total investments 11,230,387 11,145,222
Level 1 | Mutual funds | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 2,172,325 3,223,546
Total investments 127,091,890 120,858,693
Level 1 | Brunswick ESOP Company Stock Fund | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 7,567,265 6,471,937
Level 1 | Brunswick ESOP Company Stock Fund | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 32,378,124 27,325,210
Level 2 | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 2 | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 2 | Common stock | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 2 | Common stock | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 2 | Mutual funds | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 2 | Mutual funds | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 2 | Brunswick ESOP Company Stock Fund | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 2 | Brunswick ESOP Company Stock Fund | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 3 | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 3 | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 3 | Common stock | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 3 | Common stock | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 3 | Mutual funds | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 3 | Mutual funds | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Total investments 0 0
Level 3 | Brunswick ESOP Company Stock Fund | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Level 3 | Brunswick ESOP Company Stock Fund | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
NAV | EBP 154    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 145,043,187 130,222,126
Total investments 189,548 82,227
NAV | EBP 170    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 1,719,923,353 1,515,352,264
Total investments $ 2,145,071 $ 891,676