v3.26.1
Revenues from Contracts with Customers - Summary of Revenues from Contracts with Customers, and Other Sources of Revenue (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers ¥ 1,504,029 ¥ 1,352,263 ¥ 1,299,965
Other revenues [1] 50,940 40,175 38,959
Total sales of goods and real estate and services income 3,330,831 2,874,821 2,814,361
Sales of goods      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 320,653 269,050 266,390
Real estate sales      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 121,933 104,105 107,524
Asset management and servicing      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 297,626 275,929 244,508
Automobile related services      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 93,011 87,173 88,325
Facilities operation      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 102,956 83,559 76,087
Environment and energy services      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 169,047 175,651 158,075
Real estate management and brokerage      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 107,010 102,369 99,843
Real estate contract work      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 164,262 162,921 152,022
Other      
Revenue From Contract With Customers [Line Items]      
Total revenues from contracts with customers 127,531 91,506 107,191
Sales of goods, Real estate and Services [Member]      
Revenue From Contract With Customers [Line Items]      
Total sales of goods and real estate and services income ¥ 1,554,969 ¥ 1,392,438 ¥ 1,338,924
[1] Other revenues are not in the scope of revenue from contracts with customers.