Derivative Instruments - Notional Amounts Outstanding under Foreign Currency Contracts (Detail) - Not Designated as Hedging Instrument - Foreign Exchange Contract - USD ($) $ in Thousands	Dec. 31, 2015	Sep. 30, 2015
Derivative [Line Items]
Foreign exchange contracts	$ 87	$ 89
Foreign exchange contracts	(100)	(36)
Buy Currency, British Pound; Sell Currency, Norwegian Krone
Derivative [Line Items]
Foreign exchange contracts	0
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, 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	7	0
Foreign exchange contracts	0	(29)
Buy Currency, U.S. Dollar; Sell Currency, Taiwan Dollar
Derivative [Line Items]
Foreign exchange contracts	4	0
Foreign exchange contracts	0	(1)
Buy Currency, U.S. Dollar; Sell Currency, Chinese Yuan
Derivative [Line Items]
Foreign exchange contracts	0	15
Foreign exchange contracts	(73)	0
Buy Currency, U.S. Dollar; Sell Currency, British Pound
Derivative [Line Items]
Foreign exchange contracts	24	32
Foreign exchange contracts	0	0
Buy Currency, Euro; Sell Currency U.S. Dollar
Derivative [Line Items]
Foreign exchange contracts	48	40
Foreign exchange contracts	0	0
Buy Currency, Korean Won; Sell Currency, Singapore Dollar
Derivative [Line Items]
Foreign exchange contracts	0
Foreign exchange contracts	(3)
Buy Currency, Korean Won; Sell Currency, U.S. Dollar
Derivative [Line Items]
Foreign exchange contracts	0
Foreign exchange contracts	(21)
Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, One
Derivative [Line Items]
Foreign exchange contracts	2	0
Foreign exchange contracts	0	0
Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, Two
Derivative [Line Items]
Foreign exchange contracts		2
Foreign exchange contracts		0
Buy Currency, Korean Won; Sell Currency, Japanese Yen
Derivative [Line Items]
Foreign exchange contracts	0
Foreign exchange contracts	(3)
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	0	0
Long | Buy Currency, British Pound; Sell Currency, Norwegian Krone
Derivative [Line Items]
Notional Amount	172
Long | Buy Currency, British Pound; Sell Currency, Swedish Krona
Derivative [Line Items]
Notional Amount	251
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	1,761	2,157
Long | Buy Currency, U.S. Dollar; Sell Currency, Taiwan Dollar
Derivative [Line Items]
Notional Amount	819	662
Long | Buy Currency, U.S. Dollar; Sell Currency, Chinese Yuan
Derivative [Line Items]
Notional Amount	5,646	5,177
Long | Buy Currency, U.S. Dollar; Sell Currency, British Pound
Derivative [Line Items]
Notional Amount	9,395	4,308
Long | Buy Currency, Euro; Sell Currency U.S. Dollar
Derivative [Line Items]
Notional Amount	12,814	9,300
Long | Buy Currency, Korean Won; Sell Currency, Singapore Dollar
Derivative [Line Items]
Notional Amount	104
Long | Buy Currency, Korean Won; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	827
Long | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, One
Derivative [Line Items]
Notional Amount	1,266	425
Long | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, Two
Derivative [Line Items]
Notional Amount		1,336
Long | Buy Currency, Korean Won; Sell Currency, Japanese Yen
Derivative [Line Items]
Notional Amount	105
Long | Buy Currency, Singapore Dollar; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	511
Long | Buy Currency, U.S. Dollar; Sell Currency, Israeli Shekel
Derivative [Line Items]
Notional Amount	17	457
Short | Buy Currency, British Pound; Sell Currency, Norwegian Krone
Derivative [Line Items]
Notional Amount	1,500
Short | Buy Currency, British Pound; Sell Currency, Swedish Krona
Derivative [Line Items]
Notional Amount	2,100
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	1,600	1,600
Short | Buy Currency, U.S. Dollar; Sell Currency, Taiwan Dollar
Derivative [Line Items]
Notional Amount	26,900	22,000
Short | Buy Currency, U.S. Dollar; Sell Currency, Chinese Yuan
Derivative [Line Items]
Notional Amount	37,000	33,000
Short | Buy Currency, U.S. Dollar; Sell Currency, British Pound
Derivative [Line Items]
Notional Amount	13,980	6,520
Short | Buy Currency, Euro; Sell Currency U.S. Dollar
Derivative [Line Items]
Notional Amount	14,100	8,253
Short | Buy Currency, Korean Won; Sell Currency, Singapore Dollar
Derivative [Line Items]
Notional Amount	150
Short | Buy Currency, Korean Won; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	963,000
Short | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, One
Derivative [Line Items]
Notional Amount	152,000	51,000
Short | Buy Currency, U.S. Dollar; Sell Currency, Japanese Yen, Two
Derivative [Line Items]
Notional Amount		160,000
Short | Buy Currency, Korean Won; Sell Currency, Japanese Yen
Derivative [Line Items]
Notional Amount	105
Short | Buy Currency, Singapore Dollar; Sell Currency, U.S. Dollar
Derivative [Line Items]
Notional Amount	720
Short | Buy Currency, U.S. Dollar; Sell Currency, Israeli Shekel
Derivative [Line Items]
Notional Amount	$ 65	$ 1,800