Segment and geographic information (Tables)

6 Months Ended

Sep. 30, 2018

Segment and Geographic Information [Abstract]

Business segments' results

	Millions of yen
	Retail		Asset Management			Wholesale			Other (Incl. elimination)			Total
Six months ended September 30, 2017
Non-interest revenue	¥	200,633	¥	64,749		¥	270,461		¥	115,733		¥	651,576
Net interest revenue		2,837		(1,234	)		67,818			(11,416	)		58,005
Net revenue		203,470		63,515			338,279			104,317			709,581
Non-interest expenses		153,031		29,477			295,943			73,383			551,834
Income (loss) before income taxes	¥	50,439	¥	34,038		¥	42,336		¥	30,934		¥	157,747
Six months ended September 30, 2018
Non-interest revenue	¥	174,522	¥	52,302		¥	236,662		¥	56,651		¥	520,137
Net interest revenue		4,021		(1,532	)		48,288			(16,931	)		33,846
Net revenue		178,543		50,770			284,950			39,720			553,983
Non-interest expenses		146,403		31,574			287,459			75,373			540,809
Income (loss) before income taxes	¥	32,140	¥	19,196		¥	(2,509	)	¥	(35,653	)	¥	13,174
	Millions of yen
	Retail		Asset Management			Wholesale			Other (Incl. elimination)			Total
Three months ended September 30, 2017
Non-interest revenue	¥	100,360	¥	36,061		¥	123,126		¥	58,514		¥	318,061
Net interest revenue		1,426		(643	)		35,837			(5,904	)		30,716
Net revenue		101,786		35,418			158,963			52,610			348,777
Non-interest expenses		76,239		14,950			141,980			35,285			268,454
Income (loss) before income taxes	¥	25,547	¥	20,468		¥	16,983		¥	17,325		¥	80,323
Three months ended September 30, 2018
Non-interest revenue	¥	83,857	¥	25,455		¥	121,965		¥	29,514		¥	260,791
Net interest revenue		1,853		(774	)		25,695			(3,532	)		23,242
Net revenue		85,710		24,681			147,660			25,982			284,033
Non-interest expenses		73,494		15,768			142,745			50,448			282,455
Income (loss) before income taxes	¥	12,216	¥	8,913		¥	4,915		¥	(24,466	)	¥	1,578

Major components of income (loss) before income taxes in "Other"

	Millions of yen
	Six months ended September 30
	2017			2018
Net gain (loss) related to economic hedging transactions	¥	(96	)	¥	(29,825	)
Realized gain (loss) on investments in equity securities held for operating purposes		387			52
Equity in earnings of affiliates		15,430			15,155
Corporate items		1,751			(26,201	)
Other(1)		13,462			5,166
Total	¥	30,934		¥	(35,653	)
	Millions of yen
	Three months ended September 30
	2017			2018
Net gain (loss) related to economic hedging transactions	¥	558		¥	(16,018	)
Realized gain (loss) on investments in equity securities held for operating purposes		344			7
Equity in earnings of affiliates		8,408			8,536
Corporate items		1,597			(23,719	)
Other(1)		6,418			6,728
Total	¥	17,325		¥	(24,466	)

(1) Includes the impact of Nomura’s own creditworthiness.

Reconciliation of combined business segments' results included in preceding table to reported net revenue, non-interest expenses and income (loss) before income taxes

	Millions of yen
	Six months ended September 30
	2017		2018
Net revenue	¥	709,581	¥	553,983
Unrealized gain (loss) on investments in equity securities held for operating purposes		2,735		936
Consolidated net revenue	¥	712,316	¥	554,919
Non-interest expenses	¥	551,834	¥	540,809
Unrealized gain (loss) on investments in equity securities held for operating purposes		—		—
Consolidated non-interest expenses	¥	551,834	¥	540,809
Income before income taxes	¥	157,747	¥	13,174
Unrealized gain (loss) on investments in equity securities held for operating purposes		2,735		936
Consolidated income before income taxes	¥	160,482	¥	14,110
	Millions of yen
	Three months ended September 30
	2017		2018
Net revenue	¥	348,777	¥	284,033
Unrealized gain (loss) on investments in equity securities held for operating purposes		2,716		(1,111	)
Consolidated net revenue	¥	351,493	¥	282,922
Non-interest expenses	¥	268,454	¥	282,455
Unrealized gain (loss) on investments in equity securities held for operating purposes		—		—
Consolidated non-interest expenses	¥	268,454	¥	282,455
Income before income taxes	¥	80,323	¥	1,578
Unrealized gain (loss) on investments in equity securities held for operating purposes		2,716		(1,111	)
Consolidated income before income taxes	¥	83,039	¥	467

Geographic allocation of net revenue and income (loss) before income taxes from operations by geographic areas, and long-lived assets

	Millions of yen
	Six months ended September 30
	2017			2018
Net revenue(1):
Americas	¥	120,012		¥	95,033
Europe		91,922			69,801
Asia and Oceania		32,344			19,916
Subtotal		244,278			184,750
Japan		468,038			370,169
Consolidated	¥	712,316		¥	554,919
Income (loss) before income taxes:
Americas	¥	6,414		¥	(23,260	)
Europe		891			(16,799	)
Asia and Oceania		9,012			201
Subtotal		16,317			(39,858	)
Japan		144,165			53,968
Consolidated	¥	160,482		¥	14,110
	Millions of yen
	Three months ended September 30
	2017			2018
Net revenue(1):
Americas	¥	54,250		¥	41,931
Europe		47,991			34,181
Asia and Oceania		15,262			10,423
Subtotal		117,503			86,535
Japan		233,990			196,387
Consolidated	¥	351,493		¥	282,922
Income (loss) before income taxes:
Americas	¥	(1,460	)	¥	(21,576	)
Europe		(1,354	)		(11,634	)
Asia and Oceania		3,665			1,033
Subtotal		851			(32,177	)
Japan		82,188			32,644
Consolidated	¥	83,039		¥	467

(1) There is no revenue derived from transactions with a single major external customer.

	Millions of yen
	March 31, 2018		September 30, 2018
Long-lived assets:
Americas	¥	117,323	¥	124,270
Europe		67,010		68,250
Asia and Oceania		8,613		11,766
Subtotal		192,946		204,286
Japan		231,003		224,187
Consolidated	¥	423,949	¥	428,473