Summary Of Significant Accounting Policies (Consolidated Statement Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Cash flows provided by operating activities:
Net income (loss)	$ 4,029	$ 4,430	$ 8,505	$ 8,936	$ (27,529)	$ (4,582)	$ (24,698)	$ 3,636	$ 19,374
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,732	3,544	7,487	7,164	11,419	11,142	13,915	15,051	11,961
Goodwill impairment charge					62,188	22,700	62,188	22,700
Loss (gain) on sale, disposal and abandonment of assets					(35)		208	(32)	3,455
Gain on investments	(268)	(73)	(338)	(73)	(505)	(192)	(419)	(366)	(425)
Equity in income of joint ventures	(1,281)	(1,057)	(1,816)	(1,200)	(2,072)	(1,212)	(2,939)	(3,251)	(3,103)
Dividends from joint ventures	1,340	1,892	1,340	1,891	1,340	1,891	1,340	1,891	1,393
Stock-based compensation and related net tax benefits	282	625	453	1,504	1,066	2,293	2,074	2,541	2,413
Current and long-term deferred taxes, net	260	224	847	718	(21,829)	(4,880)	(26,920)	(4,680)	3,309
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable, net	4,482	(1,114)	3,205	(1,244)	3,901	305	2,568	(3,012)	(7,457)
Decrease (increase) in prepaid taxes	901	1,304	1,027	(2,836)	(2,224)	(2,246)	1,363	(1,130)	2,800
Decrease (increase) in other operating assets, net	102	(1,968)	761	(2,956)	(73)	(3,950)	1,497	(4,547)	(2,373)
Increase in accounts payable and other accrued liabilities	(3,840)	(3,929)	(2,021)	(2,908)	296	(815)	2,854	49	3,380
Increase (decrease) in other operating liabilities, net	200	244	430	(26)	608	(1,073)	3,654	(3,501)	1,678
Net cash provided by operating activities	9,939	4,122	19,880	8,970	26,551	19,381	36,685	25,349	36,405
Cash flows used by investing activities:
Acquisition of property, plant & equipment	(1,245)	(3,714)	(2,415)	(5,962)	(3,056)	(8,135)	(4,161)	(9,145)	(14,519)
Acquisition of joint ventures and businesses, net of cash acquired	(1,800)		(1,800)		(1,800)		(1,800)		(110,057)
Other investing activities, net	97	(57)	(114)	(513)	(855)	(2,355)	(1,255)	(2,534)	(849)
Net cash used by investing activities	(2,948)	(3,771)	(4,329)	(6,475)	(5,711)	(10,490)	(7,216)	(11,679)	(125,425)
Cash flows (used) provided by financing activities:
Net borrowings on revolving credit facility	(21)		(43)		(51)		(60)	(19)	(19,803)
Long–term borrowings - loan	14,000	4,300	20,000	10,300	27,500	19,600	33,800	27,691	144,797
Long–term borrowings - repayment	(13,000)		(24,500)	(8,587)	(32,000)	(21,387)	(43,000)	(27,187)	(5,300)
Dividends paid to stockholders	(5,274)	(5,229)	(10,520)	(10,429)	(15,771)	(15,658)	(21,048)	(20,897)	(20,808)
Other financing activities, net	49	(248)	(347)	(260)	(500)	(460)	(597)	(261)	(210)
Net cash (used) provided by financing activities	(4,246)	(1,177)	(15,410)	(8,976)	(20,822)	(17,905)	(30,905)	(20,673)	98,676
Effects of foreign currency translation	49	78	109	10	(52)	(41)	(475)		(143)
Net (decrease) increase in cash and cash equivalents	2,794	(748)	250	(6,471)	(34)	(9,055)	(1,911)	(7,003)	9,513
Opening balance – cash and cash equivalents	8,672	15,675	8,672	15,675	8,672	15,675	8,672	15,675	6,162
Ending balance – cash and cash equivalents	11,466	14,927	8,922	9,204	8,638	6,620	6,761	8,672	15,675
Previously Reported [Member]
Cash flows provided by operating activities:
Net income (loss)	3,247	5,043	8,210	10,276	(28,107)	(3,323)		5,696	20,100
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,894	3,450	7,662	6,976	11,607	10,860		14,924	11,631
Goodwill impairment charge					62,188	22,700		22,700
Loss (gain) on sale, disposal and abandonment of assets					(35)			(32)	3,455
Gain on investments	(146)		(203)		(369)	(118)		(282)	(317)
Equity in income of joint ventures	(573)	(1,528)	(1,108)	(2,084)	(1,364)	(2,555)		(3,881)	(3,181)
Dividends from joint ventures	1,340	1,892	1,340	1,891	1,340	1,891		1,891	1,393
Stock-based compensation and related net tax benefits	282	625	453	1,504	1,066	2,293		2,541	2,413
Current and long-term deferred taxes, net	292	7	791	284	(21,973)	(5,531)		(5,858)	2,833
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable, net	4,396	(1,114)	3,119	(1,244)	3,815	305		(3,113)	(7,636)
Decrease (increase) in prepaid taxes	466	1,449	721	(2,755)	(3,247)	(1,349)		(985)	2,774
Decrease (increase) in other operating assets, net	(88)	(1,953)	571	(2,839)	(227)	(3,479)		(4,036)	(1,925)
Increase in accounts payable and other accrued liabilities	(3,328)	(3,963)	(2,025)	(2,959)	1,379	(1,157)		(596)	3,305
Increase (decrease) in other operating liabilities, net	200	244	430	(26)	608	(1,073)		(3,501)	1,678
Net cash provided by operating activities	9,982	4,152	19,961	9,024	26,681	19,464		25,468	36,523
Cash flows used by investing activities:
Acquisition of property, plant & equipment	(1,245)	(3,714)	(2,415)	(5,962)	(3,056)	(8,135)		(9,145)	(14,519)
Acquisition of joint ventures and businesses, net of cash acquired	(1,800)		(1,800)		(1,800)				(110,057)
Other investing activities, net	(573)	(453)	(637)	(678)	(1,037)	(1,855)		(1,869)	(563)
Net cash used by investing activities	(3,618)	(4,167)	(4,852)	(6,640)	(5,893)	(9,990)		(11,014)	(125,139)
Cash flows (used) provided by financing activities:
Net borrowings on revolving credit facility	(21)		(43)		(51)			(19)	(19,803)
Long–term borrowings - loan	14,000	4,300	20,000	10,300	27,500	19,600		27,691	144,797
Long–term borrowings - repayment	(13,000)		(24,500)	(8,587)	(32,000)	(21,387)		(27,187)	(5,300)
Dividends paid to stockholders	(5,274)	(5,229)	(10,520)	(10,429)	(15,771)	(15,658)		(20,897)	(20,808)
Other financing activities, net	49	(248)	(347)	(260)	(500)	(460)		(261)	(210)
Net cash (used) provided by financing activities	(4,246)	(1,177)	(15,410)	(8,976)	(20,822)	(17,905)		(20,673)	98,676
Effects of foreign currency translation	(30)	56	108	13	4	(205)		(230)	(341)
Net (decrease) increase in cash and cash equivalents	2,088	(1,136)	(193)	(6,579)	(30)	(8,636)		(6,449)	9,719
Opening balance – cash and cash equivalents	11,184	17,633	11,184	17,633	11,184	17,633	11,184	17,633	7,914
Ending balance – cash and cash equivalents	$ 13,272	$ 16,497	$ 10,991	$ 11,054	$ 11,154	$ 8,997		$ 11,184	$ 17,633