Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Operating activities
Net income	$ 88,678	$ 90,028	$ 124,268
Depreciation	46,377	50,136	50,030
Amortization	2,691	2,641	2,629
Loss on early extinguishment of debt			3,649
Asset impairment loss	3,591	51,268	13,007
Goodwill impairment loss		2,425
Insurance settlement	(4,277)
Gain on sale of assets held for sale	(7,346)
Deferred income taxes	1,132	(13,305)	(84,193)
Payable for exchange of alternative fuel mixture credits	(388)	10,247	39,494
Provision for bad debts	663	(57)	(198)
Excess tax benefit from stock-based compensation	(2,380)	(4,062)	(2,495)
Stock-based compensation expense	5,603	4,245	4,594
Loss on disposal of equipment	1,653	1,602	1,297
Other	2,320	1,861	(492)
Accounts receivable	1,052	6,548	(14,805)
Income tax receivable	(2)		68,356
Inventories	(6,046)	(5,119)	(13,532)
Other assets	12,074	803	122
Accounts payable and other current liabilities	(11,612)	(26,349)	17,643
Net cash provided by operating activities	136,184	171,763	212,002
Investing activities
Purchases of property, plant and equipment	(109,362)	(84,940)	(57,307)
Proceeds from sale of assets	20,116	11,760
Purchase of short term investments	(32,199)	(9,213)
Proceeds from insurance settlement related to capital investment	4,277
Other	(520)	(481)	(471)
Net cash used in investing activities	(117,688)	(82,874)	(57,778)
Financing activities
Net borrowings (payments) under revolving line of credit	(17,406)	(38,343)	(609)
Payments on long-term debt and other			(140,000)
Payments for debt issuance costs			(2,586)
Payments related to early extinguishment of debt			(1,984)
Purchase of treasury shares	(9,203)	(32,916)	(9,799)
Cash used to settle net share equity awards	(938)	(1,526)	(1,186)
Net proceeds from sale of equity interests	2,503	3,054	4,011
Excess tax benefit from stock based compensation	2,380	4,062	2,495
Payment of dividend	(13,737)	(10,756)	(7,252)
Net cash used in financing activities	(36,401)	(76,425)	(156,910)
Effect of foreign currency rate fluctuations on cash	(3,249)	(4,674)	11,059
Increase (decrease) in cash and cash equivalents	(21,154)	7,790	8,373
Cash and cash equivalents at beginning of year	38,284	30,494	22,121
Cash and cash equivalents at end of year	17,130	38,284	30,494
Cash Basis [Member]
Operating activities
Deferred income taxes	$ 3,533	$ (14,454)	$ (81,565)