Acquisition (Narrative) (Details) (USD $)	3 Months Ended	6 Months Ended		0 Months Ended		0 Months Ended
	Mar. 31, 2012	Mar. 31, 2012	Apr. 02, 2011	Sep. 02, 2011 4C Solutions Inc [Member]	Sep. 30, 2011 4C Solutions Inc [Member]	May 31, 2011 MKS Inc [Member]
Revenue of acquirees since acquisition dates, actual	$ 22,300,000	$ 40,700,000
Acquisition-related cost	400,000	2,500,000
Cash paid to acquire business, net of cash acquired		1,170,000	0	14,900,000
Cash acquired from acquisition				100,000		33,200,000
Contingent purchase price included in accrued expenses and other current liabilities					1,200,000
Purchase price of acquired entity						$ 265,200,000