Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010
Cash flows from operations:
Net earnings	$ 116,791	$ 94,623	$ 116,962
Adjustments to reconcile net earnings to net cash provided by operations
Depreciation and amortization	96,552	82,355	73,546
Other amortization	347	988	203
Stock based compensation	3,792	2,066	2,031
Loss (gain) on sale of property and equipment	1,428	(80)	456
Deferred income taxes	54,589	60,861	18,171
Excess tax benefits related to stock option exercises	(1,162)	(648)	(365)
Loss on early retirement of debt		11,350
Changes in assets and liabilities
Receivables	(1,546)	(8,043)	(1,223)
Inventories	(8,647)	(26,527)	(15,886)
Prepaid expenses	(118)	(51)	87
Accounts payable	(4,510)	70,341	29,898
Accrued expenses	7,399	5,516	(6,567)
Income taxes receivable	29,508	(31,266)	(3,649)
Other, net	456	(42)	404
Net cash provided by operations	294,879	261,443	214,068
Cash flows from investing:
Purchase of property and equipment	(240,874)	(214,573)	(129,233)
Payments for acquisition of stores	(39,444)	(113,567)	(45,688)
Proceeds from sale of property and equipment	2,196	2,627	1,769
Net cash used in investing activities	(278,122)	(325,513)	(173,152)
Cash flows from financing:
Proceeds from long-term debt		569,000
Payments of long-term debt	(1,372)	(69,172)	(19,231)
Net borrowings of short-term debt	(600)	600
Proceeds from exercise of stock options	3,249	3,733	1,239
Payments of cash dividends	(22,849)	(20,467)	(17,308)
Repurchase of common stock		(501,026)
Payments of prepayment penalties		(11,350)
Excess tax benefits related to stock option exercises	1,162	648	365
Net cash used in financing activities	(20,410)	(28,034)	(34,935)
Net (decrease) increase in cash and cash equivalents	(3,653)	(92,104)	5,981
Cash and cash equivalents at beginning of year	59,572	151,676	145,695
Cash and cash equivalents at end of year	55,919	59,572	151,676
SUPPLEMENTAL DISCLOSURES OF CASH FLOWS INFORMATION
Interest, net of amount capitalized	35,403	34,691	11,677
Income taxes	(17,973)	26,113	48,825
Noncash investing and financing activities
Property and equipment acquired through notes payable and capitalized lease obligations	$ 191	$ 689	$ 2,234