Condensed Consolidating Financial Statements (Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2014	Apr. 30, 2014	Oct. 31, 2013	Apr. 30, 2013
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	$ 627,490	$ 2,185,307	$ 790,772	$ 1,747,584
Cash and cash equivalents - restricted	55,543	115,319	47,521
Receivables, net - short-term, Carrying Amount	107,705	191,618	131,701
Prepaid expenses and other current assets	285,463	198,267	225,660
Investments in available-for-sale securities	381,180	423,495
Total current assets	1,457,381	3,114,006	1,195,654
Mortgage loans held for investment, net	251,092	268,428	295,907
Investments in available-for-sale securities	9,774	4,329	465,344
Property and equipment, at cost less accumulated depreciation and amortization of $491,153, $449,738 and $446,049	318,225	304,911	311,157
Intangible assets, net	414,045	355,622	296,213
Goodwill	464,182	436,117	442,812	434,782
Investments in subsidiaries
Amounts due from affiliates	0	0	0
Other assets	176,591	210,116	267,426
Total assets	3,091,290	4,693,529	3,274,513
Customer deposits	454,860	769,785	655,129
Accounts payable, accrued expenses and other current liabilities	436,830	569,007	426,994
Accrued salaries, wages and payroll taxes	36,215	167,032	41,584
Accrued income taxes	147,000	406,655	22,475
Current portion of long-term debt	772	400,637	400,503
Total current liabilities	1,075,677	2,313,116	1,546,685
Long-term debt	505,588	505,837	506,078
Other noncurrent liabilities	271,349	318,027	266,775
Amounts due to affiliates
Total liabilities	1,852,614	3,136,980	2,319,538
Stockholders’ equity	1,238,676	1,556,549	954,975
Total liabilities and stockholders' equity	3,091,290	4,693,529	3,274,513
Block Financial Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	432,224	612,376	389,915	558,110
Cash and cash equivalents - restricted	5,431	67,463	6,795
Receivables, net - short-term, Carrying Amount	84,196	89,975	99,867
Prepaid expenses and other current assets	113,571	10,202	14,543
Investments in available-for-sale securities	381,080	423,495
Total current assets	1,016,502	1,203,511	511,120
Mortgage loans held for investment, net	251,092	268,428	295,907
Investments in available-for-sale securities			460,935
Property and equipment, at cost less accumulated depreciation and amortization of $491,153, $449,738 and $446,049	157	121	145
Intangible assets, net
Goodwill
Investments in subsidiaries
Amounts due from affiliates	10	386,818	397,526
Other assets	157,472	173,168	140,811
Total assets	1,425,233	2,032,046	1,806,444
Customer deposits	455,134	770,885	655,575
Accounts payable, accrued expenses and other current liabilities	229,262	223,677	183,342
Accrued salaries, wages and payroll taxes	2,197	2,190	1,881
Accrued income taxes	47,732	71,132	29,020
Current portion of long-term debt		399,882	399,765
Total current liabilities	734,325	1,467,766	1,269,583
Long-term debt	497,753	497,612	497,471
Other noncurrent liabilities	47,477	5,766	12,428
Amounts due to affiliates	91,909
Total liabilities	1,371,464	1,971,144	1,779,482
Stockholders’ equity	53,769	60,902	26,962
Total liabilities and stockholders' equity	1,425,233	2,032,046	1,806,444
Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	195,540	1,574,031	401,303	1,192,197
Cash and cash equivalents - restricted	50,112	47,856	40,726
Receivables, net - short-term, Carrying Amount	23,430	101,643	31,834
Prepaid expenses and other current assets	171,892	188,065	217,662
Investments in available-for-sale securities	100
Total current assets	441,074	1,911,595	691,525
Mortgage loans held for investment, net
Investments in available-for-sale securities	9,774	4,329	4,409
Property and equipment, at cost less accumulated depreciation and amortization of $491,153, $449,738 and $446,049	318,068	304,790	311,012
Intangible assets, net	414,045	355,622	296,213
Goodwill	464,182	436,117	442,812
Investments in subsidiaries	53,769	60,902	26,962
Amounts due from affiliates	92,974	397	2,167,944
Other assets	19,119	25,677	118,103
Total assets	1,813,005	3,099,429	4,058,980
Customer deposits
Accounts payable, accrued expenses and other current liabilities	206,625	344,573	243,071
Accrued salaries, wages and payroll taxes	34,018	164,842	39,703
Accrued income taxes	99,268	335,523
Current portion of long-term debt	772	755	738
Total current liabilities	340,683	845,693	283,512
Long-term debt	7,835	8,225	8,607
Other noncurrent liabilities	223,872	312,261	254,347
Amounts due to affiliates	565,397	1,028,919	397,526
Total liabilities	1,137,787	2,195,098	943,992
Stockholders’ equity	675,218	904,331	3,114,988
Total liabilities and stockholders' equity	1,813,005	3,099,429	4,058,980
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents
Cash and cash equivalents - restricted
Receivables, net - short-term, Carrying Amount	79
Prepaid expenses and other current assets
Investments in available-for-sale securities
Total current assets	79
Mortgage loans held for investment, net
Investments in available-for-sale securities
Property and equipment, at cost less accumulated depreciation and amortization of $491,153, $449,738 and $446,049
Intangible assets, net
Goodwill
Investments in subsidiaries	675,218	904,331	3,114,988
Amounts due from affiliates	565,387	642,101	0
Other assets		11,271	8,512
Total assets	1,240,684	1,557,703	3,123,500
Customer deposits
Accounts payable, accrued expenses and other current liabilities	943	757	581
Accrued salaries, wages and payroll taxes
Accrued income taxes
Current portion of long-term debt
Total current liabilities	943	757	581
Long-term debt
Other noncurrent liabilities
Amounts due to affiliates	1,065	397	2,167,944
Total liabilities	2,008	1,154	2,168,525
Stockholders’ equity	1,238,676	1,556,549	954,975
Total liabilities and stockholders' equity	1,240,684	1,557,703	3,123,500
Intersegment Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash & cash equivalents	(274)	(1,100)	(446)	(2,723)
Cash and cash equivalents - restricted
Receivables, net - short-term, Carrying Amount
Prepaid expenses and other current assets			(6,545)
Investments in available-for-sale securities
Total current assets	(274)	(1,100)	(6,991)
Mortgage loans held for investment, net
Investments in available-for-sale securities
Property and equipment, at cost less accumulated depreciation and amortization of $491,153, $449,738 and $446,049
Intangible assets, net
Goodwill
Investments in subsidiaries	(728,987)	(965,233)	(3,141,950)
Amounts due from affiliates	(658,371)	(1,029,316)	(2,565,470)
Other assets
Total assets	(1,387,632)	(1,995,649)	(5,714,411)
Customer deposits	(274)	(1,100)	(446)
Accounts payable, accrued expenses and other current liabilities
Accrued salaries, wages and payroll taxes
Accrued income taxes			(6,545)
Current portion of long-term debt
Total current liabilities	(274)	(1,100)	(6,991)
Long-term debt
Other noncurrent liabilities
Amounts due to affiliates	(658,371)	(1,029,316)	(2,565,470)
Total liabilities	(658,645)	(1,030,416)	(2,572,461)
Stockholders’ equity	(728,987)	(965,233)	(3,141,950)
Total liabilities and stockholders' equity	$ (1,387,632)	$ (1,995,649)	$ (5,714,411)