v3.26.1
Revenues from Contracts with Customers - Summary of Costs of Goods and Real Estate Sold and Service Expense (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses ¥ 2,874,583 ¥ 2,542,995 ¥ 2,453,648
Costs of goods sold      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 226,368 184,674 179,799
Costs of real estate sold      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 105,620 87,159 88,828
Asset management and servicing      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 74,079 69,377 58,376
Automobile related services      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 63,957 56,832 56,880
Facilities operation      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 88,275 69,926 65,979
Environment and energy services      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 131,409 136,426 109,923
Real estate management and brokerage      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 96,104 93,296 88,973
Real estate contract work      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 137,337 139,430 132,656
Other      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses 43,168 38,858 47,314
Expenses of costs of goods and real estate sold and services expenses      
Sales And Costs Of Goods And Real Estate And Services Income And Expenses [Line Items]      
Total expenses of costs of goods and real estate sold and services expenses ¥ 966,317 ¥ 875,978 ¥ 828,728