XML 140 R121.htm IDEA: XBRL DOCUMENT v3.5.0.1
Employee benefit plans - Net Periodic Benefit Cost of Defined Benefit Plans (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Mar. 31, 2014
Employee benefit plans      
Service cost ¥ 8,253 ¥ 7,800 ¥ 8,438
Interest cost 2,092 3,090 3,441
Expected return on plan assets (6,064) (5,732) (4,971)
Amortization of net actuarial losses 1,456 2,127 2,767
Amortization of prior service cost (1,148) (1,148) (1,149)
Net periodic benefit cost ¥ 4,589 ¥ 6,137 ¥ 8,526