Financial Instruments and Fair Value Measurements - Schedule of Fair Value and Classification of Derivative Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Asset	$ 20,310	$ 47,114
Liability	29,794	1,268
Forwards and Options [Member] \| GBP [Member]
Derivatives Fair Value [Line Items]
Asset	4,932	16,985
Liability	7,158	0
Forwards and Options [Member] \| CAD
Derivatives Fair Value [Line Items]
Asset	0	831
Liability	1,709	197
Forwards and Options [Member] \| EUR
Derivatives Fair Value [Line Items]
Asset	0	10,933
Liability	12,144	0
Forwards and Options [Member] \| JPY
Derivatives Fair Value [Line Items]
Asset	6,671	9,246
Liability	1,100	1,071
Interest Rate Hedges [Member]
Derivatives Fair Value [Line Items]
Asset	8,707	435
Liability	0	0
Net Investment Hedges [Member] \| GBP [Member]
Derivatives Fair Value [Line Items]
Asset	0	7,439
Liability	0	0
Net Investment Hedges [Member] \| CAD
Derivatives Fair Value [Line Items]
Asset	0	1,245
Liability	$ 7,683	$ 0

Aggregate fair value of all derivative assets designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

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