Condensed Consolidating Financial Statements (Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2014	Apr. 30, 2014	Jul. 31, 2013	Apr. 30, 2013
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	$ 1,429,489	$ 2,185,307	$ 1,163,876	$ 1,747,584
Cash and cash equivalents - restricted	71,917	115,319	55,477
Receivables, net - short-term, Carrying Amount	122,315	191,618	121,309
Prepaid expenses and other current assets	264,666	198,267	364,270
Investments in available-for-sale securities	403,774	423,495
Total current assets	2,292,161	3,114,006	1,704,932
Mortgage loans held for investment, net	259,732	268,428	309,681
Available-for-sale Securities, Noncurrent	4,289	4,329	487,033
Property and equipment, at cost less accumulated depreciation and amortization of $468,372, $432,681 and $446,049	314,531	304,911	286,584
Intangible assets and goodwill, net	347,890	355,622	280,455
Goodwill	478,845	436,117	435,667	434,782
Investments in subsidiaries
Amounts due from affiliates	0	0	0
Other assets	193,371	210,116	258,536
Total assets	3,890,819	4,693,529	3,762,888
Customer deposits	482,975	769,785	757,929
Accounts Payable and Accrued Liabilities, Current	485,205	569,007	443,065
Accrued Salaries, Current	30,996	167,032	32,926
Accrued Income Taxes	284,038	406,655	215,834
Long-term Debt, Current Maturities	400,705	400,637	730
Total current liabilities	1,683,919	2,313,116	1,450,484
Long-term Debt, Excluding Current Maturities	505,714	505,837	905,902
Other noncurrent liabilities	303,986	318,027	301,187
Amounts due to affiliates
Total liabilities	2,493,619	3,136,980	2,657,573
Stockholders’ equity	1,397,200	1,556,549	1,105,315
Total liabilities and stockholders' equity	3,890,819	4,693,529	3,762,888
Block Financial Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	405,512	612,376	439,100	558,110
Cash and cash equivalents - restricted	12,817	67,463	12,290
Receivables, net - short-term, Carrying Amount	86,968	89,975	94,932
Prepaid expenses and other current assets	107,725	10,202	25,681
Investments in available-for-sale securities	403,674	423,495
Total current assets	1,016,696	1,203,511	572,003
Mortgage loans held for investment, net	259,732	268,428	309,681
Available-for-sale Securities, Noncurrent			482,603
Property and equipment, at cost less accumulated depreciation and amortization of $468,372, $432,681 and $446,049	209	121	810
Intangible assets and goodwill, net
Goodwill
Investments in subsidiaries
Amounts due from affiliates	322,339	386,818	409,794
Other assets	149,930	173,168	143,234
Total assets	1,748,906	2,032,046	1,918,125
Customer deposits	483,405	770,885	761,399
Accounts Payable and Accrued Liabilities, Current	224,963	223,677	190,287
Accrued Salaries, Current	2,129	2,190	1,497
Accrued Income Taxes	30,944	71,132	35,101
Long-term Debt, Current Maturities	399,941	399,882
Total current liabilities	1,141,382	1,467,766	988,284
Long-term Debt, Excluding Current Maturities	497,682	497,612	897,107
Other noncurrent liabilities	59,458	5,766	11,793
Amounts due to affiliates
Total liabilities	1,698,522	1,971,144	1,897,184
Stockholders’ equity	50,384	60,902	20,941
Total liabilities and stockholders' equity	1,748,906	2,032,046	1,918,125
Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	1,024,407	1,574,031	728,246	1,192,197
Cash and cash equivalents - restricted	59,100	47,856	43,187
Receivables, net - short-term, Carrying Amount	35,332	101,643	25,917
Prepaid expenses and other current assets	156,924	188,065	338,589
Investments in available-for-sale securities	100
Total current assets	1,275,863	1,911,595	1,135,939
Mortgage loans held for investment, net
Available-for-sale Securities, Noncurrent	4,289	4,329	4,430
Property and equipment, at cost less accumulated depreciation and amortization of $468,372, $432,681 and $446,049	314,322	304,790	285,774
Intangible assets and goodwill, net	347,890	355,622	280,455
Goodwill	478,845	436,117	435,667
Investments in subsidiaries	50,384	60,902	20,941
Amounts due from affiliates	983	397	2,176,279
Other assets	40,046	25,677	108,326
Total assets	2,512,622	3,099,429	4,447,811
Customer deposits
Accounts Payable and Accrued Liabilities, Current	259,396	344,573	252,288
Accrued Salaries, Current	28,867	164,842	31,429
Accrued Income Taxes	253,094	335,523	180,733
Long-term Debt, Current Maturities	764	755	730
Total current liabilities	542,121	845,693	465,180
Long-term Debt, Excluding Current Maturities	8,032	8,225	8,795
Other noncurrent liabilities	239,133	312,261	289,394
Amounts due to affiliates	938,917	1,028,919	409,794
Total liabilities	1,728,203	2,195,098	1,173,163
Stockholders’ equity	784,419	904,331	3,274,648
Total liabilities and stockholders' equity	2,512,622	3,099,429	4,447,811
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents
Cash and cash equivalents - restricted
Receivables, net - short-term, Carrying Amount	15		460
Prepaid expenses and other current assets	17
Investments in available-for-sale securities
Total current assets	32		460
Mortgage loans held for investment, net
Available-for-sale Securities, Noncurrent
Property and equipment, at cost less accumulated depreciation and amortization of $468,372, $432,681 and $446,049
Intangible assets and goodwill, net
Goodwill
Investments in subsidiaries	784,419	904,331	3,274,648
Amounts due from affiliates	616,578	642,101	0
Other assets	3,395	11,271	6,976
Total assets	1,404,424	1,557,703	3,282,084
Customer deposits
Accounts Payable and Accrued Liabilities, Current	846	757	490
Accrued Salaries, Current
Accrued Income Taxes
Long-term Debt, Current Maturities
Total current liabilities	846	757	490
Long-term Debt, Excluding Current Maturities
Other noncurrent liabilities	5,395
Amounts due to affiliates	983	397	2,176,279
Total liabilities	7,224	1,154	2,176,769
Stockholders’ equity	1,397,200	1,556,549	1,105,315
Total liabilities and stockholders' equity	1,404,424	1,557,703	3,282,084
Intersegment Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	(430)	(1,100)	(3,470)	(2,723)
Cash and cash equivalents - restricted
Receivables, net - short-term, Carrying Amount
Prepaid expenses and other current assets
Investments in available-for-sale securities
Total current assets	(430)	(1,100)	(3,470)
Mortgage loans held for investment, net
Available-for-sale Securities, Noncurrent
Property and equipment, at cost less accumulated depreciation and amortization of $468,372, $432,681 and $446,049
Intangible assets and goodwill, net
Goodwill
Investments in subsidiaries	(834,803)	(965,233)	(3,295,589)
Amounts due from affiliates	(939,900)	(1,029,316)	(2,586,073)
Other assets
Total assets	(1,775,133)	(1,995,649)	(5,885,132)
Customer deposits	(430)	(1,100)	(3,470)
Accounts Payable and Accrued Liabilities, Current
Accrued Salaries, Current
Accrued Income Taxes
Long-term Debt, Current Maturities
Total current liabilities	(430)	(1,100)	(3,470)
Long-term Debt, Excluding Current Maturities
Other noncurrent liabilities
Amounts due to affiliates	(939,900)	(1,029,316)	(2,586,073)
Total liabilities	(940,330)	(1,030,416)	(2,589,543)
Stockholders’ equity	(834,803)	(965,233)	(3,295,589)
Total liabilities and stockholders' equity	$ (1,775,133)	$ (1,995,649)	$ (5,885,132)