Condensed Consolidating Financial Statements (Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Oct. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Total revenues	$ 488,426	$ 451,882		$ 767,082	$ 708,399
Cost of revenues	416,601	388,777		884,335	825,565
Selling, general and administrative	169,098	187,897		381,193	400,372
Total operating expenses	585,699	576,674		1,265,528	1,225,937
Other income (expense), net	1,028	134		3,259	4,948
Interest expense on borrowings	(24,560)	(25,940)		(67,102)	(70,026)
Loss from continuing operations before income taxes (benefit)	(120,805)	(150,598)	$ 441,500	(562,289)	(582,616)
Income taxes (benefit)	122,120	(49,386)	$ 165,400	(43,234)	(216,963)
Net loss from continuing operations	(242,925)	(101,212)		(519,055)	(365,653)
Net income (loss) from discontinued operations	(2,720)	(3,302)		(10,723)	(8,754)
Net loss	(245,645)	(104,514)		(529,778)	(374,407)
Other comprehensive income (loss)	4,848	1,759		5,925	(4,130)
Comprehensive loss	(240,797)	(102,755)		(523,853)	(378,537)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Total revenues	(16,977)	(13,207)		(22,736)	(13,351)
Cost of revenues	(8,976)	(8,751)		(9,119)	(8,895)
Selling, general and administrative	(8,001)	(4,456)		(13,617)	(4,456)
Total operating expenses	(16,977)	(13,207)		(22,736)	(13,351)
Other income (expense), net	264,012	93,265		555,080	392,305
Interest expense on borrowings	0	0		0	0
Loss from continuing operations before income taxes (benefit)	264,012	93,265		555,080	392,305
Net loss from continuing operations	264,012	93,265		555,080	392,305
Net loss	264,012	93,265		555,080	392,305
Other comprehensive income (loss)	(4,848)	(1,759)		(5,925)	4,130
Comprehensive loss	259,164	91,506		549,155	396,435
Block Financial (Issuer)
Condensed Financial Statements, Captions [Line Items]
Total revenues	55,795	53,990		85,056	80,428
Cost of revenues	33,805	33,242		46,769	47,514
Selling, general and administrative	10,823	10,693		17,614	14,905
Total operating expenses	44,628	43,935		64,383	62,419
Other income (expense), net	7,819	14,978		20,884	17,011
Interest expense on borrowings	(24,491)	(25,858)		(66,873)	(69,420)
Loss from continuing operations before income taxes (benefit)	(5,505)	(825)		(25,316)	(34,400)
Income taxes (benefit)	15,600	(2,939)		9,987	(14,695)
Net loss from continuing operations	(21,105)	2,114		(35,303)	(19,705)
Net income (loss) from discontinued operations	(2,720)	(3,282)		(10,721)	(8,733)
Net loss	(23,825)	(1,168)		(46,024)	(28,438)
Comprehensive loss	(23,825)	(1,168)		(46,024)	(28,438)
H&R Block, Inc. (Guarantor)
Condensed Financial Statements, Captions [Line Items]
Other income (expense), net	(250,732)	(106,332)		(538,995)	(379,767)
Interest expense on borrowings	0	0		0	0
Loss from continuing operations before income taxes (benefit)	(250,732)	(106,332)		(538,995)	(379,767)
Income taxes (benefit)	(5,087)	(1,818)		(9,217)	(5,360)
Net loss from continuing operations	(245,645)	(104,514)		(529,778)	(374,407)
Net income (loss) from discontinued operations	0	0		0	0
Net loss	(245,645)	(104,514)		(529,778)	(374,407)
Other comprehensive income (loss)	4,848	1,759		5,925	(4,130)
Comprehensive loss	(240,797)	(102,755)		(523,853)	(378,537)
Other Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Total revenues	449,608	411,099		704,762	641,322
Cost of revenues	391,772	364,286		846,685	786,946
Selling, general and administrative	166,276	181,660		377,196	389,923
Total operating expenses	558,048	545,946		1,223,881	1,176,869
Other income (expense), net	(20,071)	(1,777)		(33,710)	(24,601)
Interest expense on borrowings	(69)	(82)		(229)	(606)
Loss from continuing operations before income taxes (benefit)	(128,580)	(136,706)		(553,058)	(560,754)
Income taxes (benefit)	111,607	(44,629)		(44,004)	(196,908)
Net loss from continuing operations	(240,187)	(92,077)		(509,054)	(363,846)
Net income (loss) from discontinued operations		(20)		(2)	(21)
Net loss	(240,187)	(92,097)		(509,056)	(363,867)
Other comprehensive income (loss)	4,848	1,759		5,925	(4,130)
Comprehensive loss	$ (235,339)	$ (90,338)		$ (503,131)	$ (367,997)