Reclassifications Out of Accumulated Other Comprehensive Loss (AOCI) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012
Accumulated Other Comprehensive Loss [Line Items]
Cost of revenues	$ (44,313)		$ (36,736)	$ (99,369)		$ (89,291)
Interest expense	(587)		(2,594)	(2,423)		(7,824)
Operating expenses	(11,395)		(9,904)	(32,908)		(28,212)
Income from Continuing Operations before Income Tax	13,317		8,399	18,451		10,737
Income tax expense	(4,945)		(3,517)	(6,167)		(4,583)
Net Income	8,388		4,705	12,275		5,911
Reclassification out of Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss [Line Items]
Net Income	(677)	[1]		(2,005)	[1]
Reclassification out of Accumulated Other Comprehensive Loss | Gains (Losses) on Effective Cash Flow Hedge
Accumulated Other Comprehensive Loss [Line Items]
Income tax expense	34	[1]		56	[1]
Net Income	(50)	[1]		(84)	[1]
Reclassification out of Accumulated Other Comprehensive Loss | Gains (Losses) on Effective Cash Flow Hedge | Interest Rate Swap
Accumulated Other Comprehensive Loss [Line Items]
Interest expense	(84)	[1]		(140)	[1]
Reclassification out of Accumulated Other Comprehensive Loss | Gains (Losses) on Defined Benefit Plan Items
Accumulated Other Comprehensive Loss [Line Items]
Cost of revenues	(563)	[1]		(1,639)	[1]
Operating expenses	(565)	[1]		(1,703)	[1]
Income from Continuing Operations before Income Tax	(1,128)	[1]		(3,342)	[1]
Income tax expense	$ 451	[1]		$ 1,337	[1]

[1] amounts in parenthesis represent a decrease to income