Condensed Consolidating Financial Statements (Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 31, 2015	Jan. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities:	$ (1,247,200)	$ (1,120,322)
Purchases of AFS securities	(100)	(45,158)
Maturities of and payments received on AFS securities	68,013	72,502
Principal payments on mortgage loans held for investment, net	18,098	35,320
Capital expenditures	(98,876)	(125,654)
Payments made for business acquisitions, net of cash acquired	(112,163)	(37,865)
Proceeds received on notes receivable		64,865
Loans made to franchisees	(48,013)	(62,039)
Repayments from franchisees	34,164	17,893
Other, net	6,179	12,227
Net cash provided by (used in) investing activities	(132,698)	(67,909)
Repayments of commercial paper and other short-term borrowings	(457,576)	(80,930)
Proceeds from issuance of commercial paper and other short-term borrowings	1,049,062	275,914
Repayments of long-term debt	(400,000)	0
Customer banking deposits, net	515,015	(124,947)
Dividends paid	(164,905)	(164,134)
Proceeds from exercise of stock options	16,026	28,083
Other, net	(26,348)	(35,919)
Net cash used in financing activities	531,274	(101,933)
Effects of exchange rates on cash	(15,549)	(20,016)
Net decrease in cash and cash equivalents	(864,173)	(1,310,180)
Cash & cash equivalents	1,321,134	437,404
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities:		(309)
Dividends paid	(164,905)	(164,134)
Proceeds from exercise of stock options	16,026	28,083
Intercompany borrowings	159,234	142,407
Other, net	(10,355)	(6,047)
Net cash used in financing activities		309
Block Financial Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities:	(290,104)	(347,188)
Purchases of AFS securities		(45,158)
Maturities of and payments received on AFS securities	68,013	72,502
Principal payments on mortgage loans held for investment, net	18,098	35,320
Capital expenditures	(119)	(59)
Loans made to franchisees	(47,835)	(62,039)
Repayments from franchisees	33,927	17,893
Intercompany payments/investments in subsidiaries	(128,713)	(122,216)
Other, net	(1,925)	6,384
Net cash provided by (used in) investing activities	(58,554)	(97,373)
Repayments of commercial paper and other short-term borrowings	(457,576)	(80,930)
Proceeds from issuance of commercial paper and other short-term borrowings	1,049,062	275,914
Repayments of long-term debt	(400,000)
Customer banking deposits, net	514,183	(127,050)
Net cash used in financing activities	705,669	67,934
Net decrease in cash and cash equivalents	357,011	(376,627)
Cash & cash equivalents	969,387	181,483
Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash used in operating activities:	(957,096)	(772,825)
Purchases of AFS securities	(100)
Capital expenditures	(98,757)	(125,595)
Payments made for business acquisitions, net of cash acquired	(112,163)	(37,865)
Proceeds received on notes receivable		64,865
Loans made to franchisees	(178)
Repayments from franchisees	237
Intercompany payments/investments in subsidiaries	(159,234)	(142,407)
Other, net	8,104	5,843
Net cash provided by (used in) investing activities	(362,091)	(235,159)
Intercompany borrowings	128,713	122,216
Other, net	(15,993)	(29,872)
Net cash used in financing activities	112,720	92,344
Effects of exchange rates on cash	(15,549)	(20,016)
Net decrease in cash and cash equivalents	(1,222,016)	(935,656)
Cash & cash equivalents	352,015	256,541
Intersegment Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Intercompany payments/investments in subsidiaries	287,947	264,623
Net cash provided by (used in) investing activities	287,947	264,623
Customer banking deposits, net	832	2,103
Intercompany borrowings	(287,947)	(264,623)
Net cash used in financing activities	(287,115)	(262,520)
Net decrease in cash and cash equivalents	832	2,103
Cash & cash equivalents	$ (268)	$ (620)