Quarterly Financial Data (Unaudited) - Consolidated Balance Sheets (Details) (USD $)	Jun. 30, 2013	Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2009
Cash and cash equivalents	$ 2,678,000	$ 5,525,000		$ 5,218,000		$ 2,545,000		$ 3,906,000		$ 3,463,000		$ 4,121,000		$ 4,552,000		$ 6,081,000		$ 4,149,000		$ 20,038,000
Restricted cash	8,084,000	3,751,000		3,599,000		129,000		1,612,000		1,774,000		1,813,000		628,000		460,000
Short-term investments	20,546,000	20,769,000		20,553,000		20,486,000		19,736,000		18,486,000		17,632,000		15,825,000		24,414,000
Accounts and notes receivable, net	43,922,000	42,793,000		43,752,000		43,139,000		40,736,000		41,685,000		44,765,000		44,554,000		43,501,000
Inventories	60,867,000	67,273,000		68,385,000		69,924,000		65,981,000		75,451,000		77,874,000		83,098,000		79,449,000
Income tax receivable	409,000	117,000		472,000		369,000		762,000		830,000		178,000		168,000		448,000
Prepaid expenses	3,243,000	2,800,000		2,740,000		3,091,000		3,445,000		2,791,000		3,196,000		2,249,000		2,747,000
Total current assets	139,749,000	143,028,000		144,719,000		139,683,000		136,178,000		144,480,000		149,579,000		151,074,000		157,100,000
Property, plant and equipment, net	92,159,000	93,838,000		98,160,000		103,317,000		108,137,000		106,855,000		105,031,000		108,944,000		114,340,000
Goodwill						0		0		5,310,000						5,310,000
Intangible assets, net	6,277,000	6,586,000		6,929,000		7,272,000		7,615,000		8,232,000		13,902,000		14,270,000		9,329,000
Other assets	5,484,000	5,247,000		5,273,000		5,358,000		5,125,000		4,839,000		4,877,000		4,919,000		4,963,000
Deferred income taxes	467,000	861,000		861,000		861,000		861,000		1,007,000		1,007,000		1,007,000		1,008,000
Total assets	244,136,000	249,560,000		255,942,000		256,491,000		257,916,000		270,723,000		274,396,000		280,214,000		292,050,000
Accounts payable	27,740,000	29,878,000		30,453,000		29,196,000		27,266,000		31,688,000		39,818,000		38,146,000		42,422,000
Accrued payroll expenses	19,757,000	15,372,000		17,009,000		18,341,000		19,130,000		18,040,000		18,525,000		16,171,000		16,958,000
Short-term borrowings under revolving credit facility	9,654,000	9,912,000		15,074,000		24,996,000		29,126,000		28,702,000		25,971,000		33,398,000		31,362,000
Short-term obligations under capital leases	3,409,000	3,435,000		3,527,000		3,683,000		3,737,000		2,745,000		1,674,000		1,588,000		1,570,000
Short term derivative liability	9,896,000	5,916,000		6,292,000		29,000		737,000		2,585,000		794,000		3,283,000		1,729,000
Deferred income taxes	923,000	1,445,000		1,445,000		1,445,000		1,445,000		476,000		476,000		476,000		476,000
Other current liabilities	5,171,000	6,728,000		5,242,000		5,268,000		5,296,000		5,287,000		4,276,000		4,063,000		4,527,000
Total current liabilities	76,550,000	72,686,000		79,042,000		82,958,000		86,737,000		89,523,000		91,534,000		97,125,000		99,044,000
Long-term borrowings under revolving credit facility	10,000,000	10,000,000		10,000,000				0
Accrued postretirement benefits	16,076,000	22,989,000		22,878,000		22,815,000		22,526,000		19,239,000		19,172,000		19,027,000		18,996,000
Other long-term liabilities-capital leases	8,759,000	9,552,000		10,617,000		11,368,000		12,130,000		9,759,000		6,254,000		6,664,000		7,066,000
Accrued pension liabilities	43,800,000	47,651,000		47,456,000		47,217,000		48,191,000		26,909,000		28,173,000		24,993,000		28,048,000
Accrued workers' compensation liabilities	5,132,000	4,022,000		4,022,000		4,131,000		4,131,000		3,821,000		3,624,000		3,639,000		3,639,000
Deferred income taxes	852,000	759,000		648,000		649,000		649,000		1,842,000		1,842,000		1,842,000		1,842,000
Total liabilities	162,298,000	167,659,000		174,663,000		169,138,000		174,364,000		151,093,000		150,599,000		153,290,000		158,635,000
Commitments and contingencies
Preferred stock	0	0		0		0		0		0		0		0		0
Common stock	16,454,000	16,449,000		16,342,000		16,314,000		16,309,000		16,281,000		16,262,000		16,187,000		16,186,000
Additional paid-in capital	34,654,000	33,728,000		31,906,000		35,653,000		34,834,000		34,093,000		33,071,000		37,259,000		36,470,000
Retained earnings	94,080,000	97,056,000		98,363,000		105,519,000		102,542,000		112,814,000		118,023,000		121,837,000		129,118,000
Unearned ESOP shares	(20,836,000)	(20,836,000)		(20,836,000)		(25,637,000)		(25,637,000)		(25,636,000)		(25,637,000)		(30,437,000)		(30,437,000)
Less accumulated other comprehensive loss	(42,514,000)	(44,496,000)		(44,496,000)		(44,496,000)		(44,496,000)		(17,922,000)		(17,922,000)		(17,922,000)		(17,922,000)
Total stockholders' equity	81,838,000	81,901,000		81,279,000		87,353,000		83,552,000		119,630,000		123,797,000		126,924,000		133,415,000		161,744,000
Total liabilities and stockholders' equity	244,136,000	249,560,000		255,942,000		256,491,000		257,916,000		270,723,000		274,396,000		280,214,000		292,050,000
Previously Reported
Cash and cash equivalents		5,525,000		5,218,000		2,545,000		3,906,000		3,463,000		4,121,000		4,552,000		6,081,000		4,149,000		20,038,000
Restricted cash		3,751,000		0		0		0		0		0		0		0
Short-term investments		20,769,000		20,570,000		20,591,000		21,021,000		18,715,000		18,881,000		16,193,000		24,874,000
Accounts and notes receivable, net		42,793,000		43,752,000		43,139,000		40,736,000		41,685,000		44,765,000		44,554,000		43,501,000
Inventories		67,273,000		68,385,000		69,924,000		65,981,000		75,762,000		78,185,000		83,408,000		79,759,000
Income tax receivable		139,000		478,000		388,000		762,000		825,000		170,000		161,000		448,000
Prepaid expenses		2,800,000		2,740,000		3,091,000		3,445,000		2,792,000		3,196,000		2,249,000		2,747,000
Total current assets		143,050,000		141,143,000		139,678,000		135,851,000		143,242,000		149,318,000		151,117,000		157,410,000
Property, plant and equipment, net		93,837,000		98,159,000		103,315,000		108,135,000		106,622,000		104,798,000		108,711,000		114,107,000
Goodwill						0				5,310,000						5,310,000
Intangible assets, net		6,586,000		6,929,000		7,272,000		7,615,000		8,232,000		13,902,000		14,270,000		9,329,000
Other assets		3,026,000		3,052,000		3,138,000		2,904,000		2,766,000		2,803,000		2,846,000		2,892,000
Deferred income taxes		854,000		854,000		854,000		854,000		1,005,000		1,005,000		1,005,000		1,005,000
Total assets		247,353,000		250,137,000		254,257,000		255,359,000		267,177,000		271,826,000		277,949,000		290,053,000
Accounts payable		30,909,000		31,594,000		29,201,000		27,676,000		31,688,000		39,818,000		38,414,000		42,473,000
Accrued payroll expenses		16,735,000		18,372,000		19,704,000		20,494,000		16,757,000		17,243,000		14,888,000		15,675,000
Short-term borrowings under revolving credit facility		9,912,000		15,074,000		24,996,000		29,126,000		28,702,000		25,971,000		33,398,000		31,362,000
Short-term obligations under capital leases		3,435,000		3,527,000		3,683,000		3,737,000		2,745,000		1,674,000		1,588,000		1,570,000
Short term derivative liability		0		0		0		0		0		0		0		0
Deferred income taxes		1,480,000		1,479,000		1,480,000		1,480,000		500,000		500,000		500,000		500,000
Other current liabilities		16,492,000		11,691,000		10,148,000		10,176,000		12,005,000		10,183,000		12,495,000		11,882,000
Total current liabilities		78,963,000		81,737,000		89,212,000		92,689,000		92,397,000		95,389,000		101,283,000		103,462,000
Long-term borrowings under revolving credit facility		10,000,000		10,000,000
Accrued postretirement benefits		35,393,000		35,158,000		34,970,000		34,557,000		24,715,000		24,352,000		23,911,000		23,585,000
Other long-term liabilities-capital leases		9,552,000		10,617,000		11,368,000		12,130,000		9,759,000		6,254,000		6,664,000		7,066,000
Accrued pension liabilities		41,973,000		41,778,000		41,539,000		42,513,000		21,231,000		22,495,000		19,316,000		22,371,000
Accrued workers' compensation liabilities		4,022,000		4,022,000		4,131,000		4,131,000		3,821,000		3,624,000		3,639,000		3,639,000
Deferred income taxes		718,000		607,000		607,000		607,000		1,815,000		1,815,000		1,815,000		1,815,000
Total liabilities		180,621,000		183,919,000		181,827,000		186,627,000		153,738,000		153,929,000		156,628,000		161,938,000
Preferred stock		0		0		0		0		0		0		0		0
Common stock		16,449,000		16,342,000		16,314,000		16,309,000		16,281,000		16,262,000		16,187,000		16,186,000
Additional paid-in capital		33,728,000		31,906,000		35,653,000		34,834,000		34,093,000		33,071,000		37,259,000		36,470,000
Retained earnings		94,620,000		96,035,000		103,329,000		100,455,000		112,589,000		118,089,000		122,200,000		129,784,000
Unearned ESOP shares		(20,836,000)		(20,836,000)		(25,637,000)		(25,637,000)		(25,636,000)		(25,637,000)		(30,437,000)		(30,437,000)
Less accumulated other comprehensive loss		(57,229,000)		(57,229,000)		(57,229,000)		(57,229,000)		(23,888,000)		(23,888,000)		(23,888,000)		(23,888,000)
Total stockholders' equity		66,732,000		66,218,000		72,430,000		68,732,000		113,439,000		117,897,000		121,321,000		128,115,000		165,595,000
Total liabilities and stockholders' equity		247,353,000		250,137,000		254,257,000		255,359,000		267,177,000		271,826,000		277,949,000		290,053,000
Adjustments
Cash and cash equivalents		0	[1]	0	[1]	0	[1]	0	[1],[2],[3]	0	[1]	0	[1]	0	[1]	0	[1],[2],[4]	0	[4],[5]	0	[5]
Restricted cash		0	[1]	3,599,000	[1]	129,000	[1]	1,612,000	[2]	1,774,000	[1]	1,813,000	[1]	628,000	[1]	460,000	[2]
Short-term investments		0	[1]	(17,000)	[1]	(105,000)	[1]	(1,285,000)	[2]	(229,000)	[1]	(1,249,000)	[1]	(368,000)	[1]	(460,000)	[2]
Accounts and notes receivable, net		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Inventories		0	[1]	0	[1]	0	[1]	0	[2]	(311,000)	[1]	(311,000)	[1]	(310,000)	[1]	(310,000)	[2]
Income tax receivable		(22,000)	[1]	(6,000)	[1]	(19,000)	[1]	0	[2]	5,000	[1]	8,000	[1]	7,000	[1]	0	[2]
Prepaid expenses		0	[1]	0	[1]	0	[1]	0	[2]	(1,000)	[1]	0	[1]	0	[1]	0	[2]
Total current assets		(22,000)	[1]	3,576,000	[1]	5,000	[1]	327,000	[2]	1,238,000	[1]	261,000	[1]	(43,000)	[1]	(310,000)	[2]
Property, plant and equipment, net		1,000	[1]	1,000	[1]	2,000	[1]	2,000	[2]	233,000	[1]	233,000	[1]	233,000	[1]	233,000	[2]
Goodwill						0	[1]			0	[1]					0	[2]
Intangible assets, net		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Other assets		2,221,000	[1]	2,221,000	[1]	2,220,000	[1]	2,221,000	[2]	2,073,000	[1]	2,074,000	[1]	2,073,000	[1]	2,071,000	[2]
Deferred income taxes		7,000	[1]	7,000	[1]	7,000	[1]	7,000	[2]	2,000	[1]	2,000	[1]	2,000	[1]	3,000	[2]
Total assets		2,207,000	[1]	5,805,000	[1]	2,234,000	[1]	2,557,000	[2]	3,546,000	[1]	2,570,000	[1]	2,265,000	[1]	1,997,000	[2]
Accounts payable		(1,031,000)	[1]	(1,141,000)	[1]	(5,000)	[1]	(410,000)	[2]	0	[1]	0	[1]	(268,000)	[1]	(51,000)	[2]
Accrued payroll expenses		(1,363,000)	[1]	(1,363,000)	[1]	(1,363,000)	[1]	(1,364,000)	[2]	1,283,000	[1]	1,282,000	[1]	1,283,000	[1]	1,283,000	[2]
Short-term borrowings under revolving credit facility		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Short-term obligations under capital leases		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Short term derivative liability		5,916,000	[1]	6,292,000	[1]	29,000	[1]	737,000	[2]	2,585,000	[1]	794,000	[1]	3,283,000	[1]	1,729,000
Deferred income taxes		(35,000)	[1]	(34,000)	[1]	(35,000)	[1]	(35,000)	[2]	(24,000)	[1]	(24,000)	[1]	(24,000)	[1]	(24,000)	[2]
Other current liabilities		(9,764,000)	[1]	(6,449,000)	[1]	(4,880,000)	[1]	(4,880,000)	[2]	(6,718,000)	[1]	(5,907,000)	[1]	(8,432,000)	[1]	(7,355,000)	[2]
Total current liabilities		(6,277,000)	[1]	(2,695,000)	[1]	(6,254,000)	[1]	(5,952,000)	[2]	(2,874,000)	[1]	(3,855,000)	[1]	(4,158,000)	[1]	(4,418,000)	[2]
Long-term borrowings under revolving credit facility		0	[1]	0	[1]
Accrued postretirement benefits		(12,404,000)	[1]	(12,280,000)	[1]	(12,155,000)	[1]	(12,031,000)	[2]	(5,476,000)	[1]	(5,180,000)	[1]	(4,884,000)	[1]	(4,589,000)	[2]
Other long-term liabilities-capital leases		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Accrued pension liabilities		5,678,000	[1]	5,678,000	[1]	5,678,000	[1]	5,678,000	[2]	5,678,000	[1]	5,678,000	[1]	5,677,000	[1]	5,677,000	[2]
Accrued workers' compensation liabilities		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Deferred income taxes		41,000	[1]	41,000	[1]	42,000	[1]	42,000	[2]	27,000	[1]	27,000	[1]	27,000	[1]	27,000	[2]
Total liabilities		(12,962,000)	[1]	(9,256,000)	[1]	(12,689,000)	[1]	(12,263,000)	[2]	(2,645,000)	[1]	(3,330,000)	[1]	(3,338,000)	[1]	(3,303,000)	[2]
Preferred stock		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Common stock		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Additional paid-in capital		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]	0	[1]	0	[1]	0	[2]
Retained earnings		2,436,000	[1]	2,328,000	[1]	2,190,000	[1]	2,087,000	[2]	225,000	[1]	(66,000)	[1]	(363,000)	[1]	(666,000)	[2]
Unearned ESOP shares		0	[1]	0	[1]	0	[1]	0	[2]	0	[1]			0	[1]	0	[2]
Less accumulated other comprehensive loss		12,733,000	[1]	12,733,000	[1]	12,733,000	[1]	12,733,000	[2]	5,966,000	[1]	5,966,000	[1]	5,966,000	[1]	5,966,000	[2]
Total stockholders' equity		15,169,000	[1]	15,061,000	[1]	14,923,000	[1]	14,820,000	[2]	6,191,000	[1]	5,900,000	[1]	5,603,000	[1]	5,300,000	[2]	(3,851,000)
Total liabilities and stockholders' equity		$ 2,207,000	[1]	$ 5,805,000	[1]	$ 2,234,000	[1]	$ 2,557,000	[2]	$ 3,546,000	[1]	$ 2,570,000	[1]	$ 2,265,000	[1]	$ 1,997,000	[2]

[1] For details see the introduction section included in Note 2.

[2] For details see the introduction section included elsewhere in this Note 2.

[3] See the introduction section included elsewhere in this Note 2.

[4] (1)See the introduction section included elsewhere in this Note 2.

[5] _______________ (1)See the introduction section included elsewhere in this Note 2.