Financial Instruments and Fair Value Measurements - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Remaining cash equivalents	$ 584,767	$ 605,536	$ 584,767
Maturity period of cash equivalents at the time of purchase		Three months or less
Maturity period of instruments in short term investments		Three months and less than one year
Fair value of long-term debt	2,839,697	4,317,059	2,839,697
Transfer of assets in and out of level 1, 2 and 3 measurements during the period		0	0
Transfer of liabilities in and out of level 1, 2 and 3 measurements during the period		0	0
Impairment charge recorded to Research and development expense, resulting from discontinuance of a research program within the Diagnostic Systems unit	9,270
Government Related Account [Member] | ITALY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance on government-related account receivable		71,390
Government Related Account [Member] | SPAIN
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance on government-related account receivable		42,866
4.55% Notes Due 2013 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debt		200,000
Debt instrument, interest rate		4.55%
Fair value of debt reclassified from long term to short term		$ 206,452