Derivative Instruments - Notional Amounts Outstanding under Foreign Currency Contracts (Detail) - Not Designated as Hedging Instrument - Foreign Exchange Contract - USD ($) $ in Thousands	Jun. 30, 2016	Sep. 30, 2015
Derivative [Line Items]
Foreign exchange contracts	$ 22	$ 89
Foreign exchange contracts	(204)	(36)
Buy Currency, British Pound; Sell Currency, Norwegian Krone
Derivative [Line Items]
Foreign exchange contracts	0
Foreign exchange contracts	(1)
Buy Currency, Japanese Yen; Sell Currency, U.S. Dollar
Derivative [Line Items]
Foreign exchange contracts	3
Foreign exchange contracts	0
Buy Currency, British Pound; Sell Currency, Swedish Krona
Derivative [Line Items]
Foreign exchange contracts	1
Foreign exchange contracts	0
Buy Currency, Korean Won; Sell Currency, U.S. Dollar
Derivative [Line Items]
Foreign exchange contracts	0
Foreign exchange contracts	(19)
Buy Currency, U.S. Dollar; Sell Currency, Korean Won
Derivative [Line Items]
Foreign exchange contracts		0
Foreign exchange contracts		(6)
Buy Currency, British Pound; Sell Currency, Euro
Derivative [Line Items]
Foreign exchange contracts	17	0
Foreign exchange contracts	0	(29)
Buy Currency, U.S. Dollar; Sell Currency, Taiwan Dollar
Derivative [Line Items]
Foreign exchange contracts	0	0
Foreign exchange contracts	(1)	(1)
Buy Currency, U.S. Dollar; Sell Currency, Chinese Yuan
Derivative [Line Items]
Foreign exchange contracts	0	15
Foreign exchange contracts	(67)	0
Buy Currency, U.S. Dollar; Sell Currency, British Pound
Derivative [Line Items]
Foreign exchange contracts	0	32
Foreign exchange contracts	(89)	0
Buy Currency, Euro; Sell Currency U.S. Dollar
Derivative [Line Items]
Foreign exchange contracts	0	40
Foreign exchange contracts	(26)	0
Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, One
Derivative [Line Items]
Foreign exchange contracts		0
Foreign exchange contracts		0
Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, Two
Derivative [Line Items]
Foreign exchange contracts		2
Foreign exchange contracts		0
Buy Currency, Singapore Dollar; Sell Currency, U.S. Dollar
Derivative [Line Items]
Foreign exchange contracts	1
Foreign exchange contracts	0
Buy Currency, U.S. Dollar; Sell Currency, Israeli Shekel
Derivative [Line Items]
Foreign exchange contracts	0	0
Foreign exchange contracts	(1)	0
Long | Buy Currency, British Pound; Sell Currency, Norwegian Krone
Derivative [Line Items]
Notional Amount	210
Long | Buy Currency, Japanese Yen; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	959
Long | Buy Currency, British Pound; Sell Currency, Swedish Krona
Derivative [Line Items]
Notional Amount	212
Long | Buy Currency, Korean Won; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	2,298
Long | Buy Currency, U.S. Dollar; Sell Currency, Korean Won
Derivative [Line Items]
Notional Amount		1,543
Long | Buy Currency, British Pound; Sell Currency, Euro
Derivative [Line Items]
Notional Amount	1,560	2,157
Long | Buy Currency, U.S. Dollar; Sell Currency, Taiwan Dollar
Derivative [Line Items]
Notional Amount	427	662
Long | Buy Currency, U.S. Dollar; Sell Currency, Chinese Yuan
Derivative [Line Items]
Notional Amount	5,801	5,177
Long | Buy Currency, U.S. Dollar; Sell Currency, British Pound
Derivative [Line Items]
Notional Amount	11,729	4,308
Long | Buy Currency, Euro; Sell Currency U.S. Dollar
Derivative [Line Items]
Notional Amount	6,638	9,300
Long | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, One
Derivative [Line Items]
Notional Amount		425
Long | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, Two
Derivative [Line Items]
Notional Amount		1,336
Long | Buy Currency, Singapore Dollar; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	1,043
Long | Buy Currency, U.S. Dollar; Sell Currency, Israeli Shekel
Derivative [Line Items]
Notional Amount	460	457
Short | Buy Currency, British Pound; Sell Currency, Norwegian Krone
Derivative [Line Items]
Notional Amount	1,800
Short | Buy Currency, Japanese Yen; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	98,000
Short | Buy Currency, British Pound; Sell Currency, Swedish Krona
Derivative [Line Items]
Notional Amount	1,800
Short | Buy Currency, Korean Won; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	2,705,000
Short | Buy Currency, U.S. Dollar; Sell Currency, Korean Won
Derivative [Line Items]
Notional Amount		1,852,000
Short | Buy Currency, British Pound; Sell Currency, Euro
Derivative [Line Items]
Notional Amount	1,400	1,600
Short | Buy Currency, U.S. Dollar; Sell Currency, Taiwan Dollar
Derivative [Line Items]
Notional Amount	13,900	22,000
Short | Buy Currency, U.S. Dollar; Sell Currency, Chinese Yuan
Derivative [Line Items]
Notional Amount	39,000	33,000
Short | Buy Currency, U.S. Dollar; Sell Currency, British Pound
Derivative [Line Items]
Notional Amount	8,880	6,520
Short | Buy Currency, Euro; Sell Currency U.S. Dollar
Derivative [Line Items]
Notional Amount	6,000	8,253
Short | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, One
Derivative [Line Items]
Notional Amount		51,000
Short | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, Two
Derivative [Line Items]
Notional Amount		160,000
Short | Buy Currency, Singapore Dollar; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	1,420
Short | Buy Currency, U.S. Dollar; Sell Currency, Israeli Shekel
Derivative [Line Items]
Notional Amount	$ 1,797	$ 1,800