Guarantor/Non-guarantor Unaudited Condensed Consolidated Financial Information - Condensed Consolidating Statement of Operations and Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Condensed Income Statements, Captions [Line Items]
Contract revenue	$ 207,377	$ 220,947	$ 585,723	$ 646,557
Direct contract expense	162,330	174,314	456,624	509,911
Gross profit	45,047	46,633	129,099	136,646
Operating expenses	19,503	20,929	59,088	64,841
General and administrative	17,709	14,017	55,255	39,025
Operating income (loss)	7,835	11,687	14,756	32,780
Other income (expense):
Interest income	15	10	43	44
Interest expense	(19,320)	(18,982)	(57,978)	(56,814)
Other	(54)	(24)	(101)	16
Gain on debt extinguishment		1,966		1,966
Total other (expense) income	(19,359)	(17,030)	(58,036)	(54,788)
(Loss) income before taxes	(11,524)	(5,343)	(43,280)	(22,008)
Income tax expense	(1,742)	(1,744)	(5,236)	(5,231)
Net income (loss)	(13,266)	(7,087)	(48,516)	(27,239)
Other comprehensive income
Postretirement actuarial gains
Comprehensive income (loss)	(13,266)	(7,087)	(48,516)	(27,239)
Eliminations [Member]
Other income (expense):
Equity in net income (loss) of subsidiaries	(293)	146	(987)	(272)
Total other (expense) income	(293)	146	(987)	(272)
(Loss) income before taxes	(293)	146	(987)	(272)
Net income (loss)	(293)	146	(987)	(272)
Other comprehensive income
Postretirement actuarial gains
Comprehensive income (loss)	(293)	146	(987)	(272)
Parent [Member]
Condensed Income Statements, Captions [Line Items]
Contract revenue	205,339	218,344	579,588	639,186
Direct contract expense	161,221	172,741	453,104	505,326
Gross profit	44,118	45,603	126,484	133,860
Operating expenses	19,045	20,365	57,716	63,034
General and administrative	17,526	13,370	55,005	38,283
Operating income (loss)	7,547	11,868	13,763	32,543
Other income (expense):
Interest income	15	10	43	44
Interest expense	(19,320)	(18,982)	(57,978)	(56,814)
Other	(54)	(59)	(101)	(19)
Gain on debt extinguishment		1,966		1,966
Equity in net income (loss) of subsidiaries	293	(146)	987	272
Total other (expense) income	(19,066)	(17,211)	(57,049)	(54,551)
(Loss) income before taxes	(11,519)	(5,343)	(43,286)	(22,008)
Income tax expense	(1,747)	(1,744)	(5,230)	(5,231)
Net income (loss)	(13,266)	(7,087)	(48,516)	(27,239)
Other comprehensive income
Postretirement actuarial gains
Comprehensive income (loss)	(13,266)	(7,087)	(48,516)	(27,239)
Guarantor Companies [Member]
Condensed Income Statements, Captions [Line Items]
Contract revenue	1,734	2,414	5,356	6,969
Direct contract expense	944	1,476	3,102	4,241
Gross profit	790	938	2,254	2,728
Operating expenses	356	460	1,068	1,578
General and administrative	163	632	211	683
Operating income (loss)	271	(154)	975	467
Other income (expense):
Other		35		35
Total other (expense) income		35		35
(Loss) income before taxes	271	(119)	975	502
Net income (loss)	271	(119)	975	502
Other comprehensive income
Postretirement actuarial gains
Comprehensive income (loss)	271	(119)	975	502
Non-Guarantor Companies [Member]
Condensed Income Statements, Captions [Line Items]
Contract revenue	304	189	779	402
Direct contract expense	165	97	418	344
Gross profit	139	92	361	58
Operating expenses	102	104	304	229
General and administrative	20	15	39	59
Operating income (loss)	17	(27)	18	(230)
Other income (expense):
(Loss) income before taxes	17	(27)	18	(230)
Income tax expense	5		(6)
Net income (loss)	22	(27)	12	(230)
Other comprehensive income
Postretirement actuarial gains
Comprehensive income (loss)	$ 22	$ (27)	$ 12	$ (230)

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