Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010
Cash flows from operating activities:
Net income	$ 28,917	$ 123,536	$ 70,676
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	82,256	74,866	63,418
Deferred income taxes	8,321	21,004	10,891
Undistributed equity in earnings of joint ventures	(2,307)	(4,622)	(3,076)
Share-based compensation expense	8,793	13,655	11,035
Excess tax benefit from share-based payment arrangements	(817)	(689)	128
(Gain) loss on disposal of a business and other assets	(135)	1,529	16,943
Net gain on derivatives	0	(772)	(4,299)
Unrealized foreign exchange (gain) loss, net	(334)	758	0
Bad debt expense (recoveries), net	688	334	(255)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	81,701	(91,715)	(11,569)
Inventories	94,095	(45,268)	(108,770)
Income taxes	(20,018)	22,703	33,277
Prepaid expenses and other current assets	(4,010)	(11,486)	(2,640)
Intangibles and other long-term assets	(82)	(133)	(206)
Accounts payable	(26,074)	45,447	8,479
Accrued payroll and related liabilities	(13,161)	2,276	12,010
Other accrued liabilities	6,500	(15,676)	(2,519)
Environmental liabilities	(2,201)	(97)	(2,335)
Other long-term liabilities	253	(167)	(2,128)
Distributed equity in earnings of joint ventures	2,405	4,980	430
Net cash provided by operating activities	244,790	140,463	89,490
Cash flows from investing activities:
Capital expenditures	(78,560)	(104,964)	(64,324)
Acquisitions, net of cash acquired	(6,567)	(293,880)	(40,944)
Joint venture payments, net	(92)	(1,587)	(340)
Proceeds from sale of a business and other assets	953	530	41,319
Net cash used in investing activities	(84,266)	(399,901)	(64,289)
Cash flows from financing activities:
Proceeds from line of credit	495,500	655,500	402,600
Repayment of line of credit	(495,500)	(655,500)	(402,600)
Borrowings from long-term debt	439,070	811,531	577,900
Repayment of long-term debt	(507,745)	(508,675)	(589,242)
Debt financing fees	(1,282)	(5,310)	0
Repurchase of Class A common stock	(33,194)	(10,303)	(17,147)
Taxes paid related to net share settlement of share-based payment arrangements	(2,307)	(3,800)	(3,599)
Excess tax benefit from share-based payment arrangements	817	689	(128)
Stock options exercised	608	567	937
Contributions from noncontrolling interest	4,008	0	0
Distributions to noncontrolling interests	(4,087)	(2,863)	(3,003)
Contingent consideration paid relating to business acquisitions	(4,485)	0	0
Dividends paid	(11,455)	(1,885)	(1,416)
Net cash (used in) provided by financing activities	(120,052)	279,951	(35,698)
Effect of exchange rate changes on cash	(71)	(1,393)	(187)
Net increase (decrease) in cash and cash equivalents	40,401	19,120	(10,684)
Cash and cash equivalents as of beginning of year	49,462	30,342	41,026
Cash and cash equivalents as of end of year	89,863	49,462	30,342
Cash paid (received) during the year for:
Interest	10,968	7,072	2,569
Income taxes paid (refunds received), net	$ 24,517	$ 14,330	$ (3,783)