Financial Instruments and Fair Value Measurements - Foreign Currency Contracts Activity (Detail) |
12 Months Ended | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Dec. 31, 2017
USD ($)
Derivative
CAD / $
£ / $
€ / $
¥ / $
|
Dec. 31, 2017
GBP (£)
Derivative
CAD / $
£ / $
€ / $
¥ / $
|
Dec. 31, 2017
JPY (¥)
Derivative
CAD / $
£ / $
€ / $
¥ / $
|
Dec. 31, 2017
CAD
Derivative
CAD / $
£ / $
€ / $
¥ / $
|
Dec. 31, 2017
EUR (€)
Derivative
CAD / $
£ / $
€ / $
¥ / $
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2016
GBP (£)
|
Dec. 31, 2016
JPY (¥)
|
Dec. 31, 2016
CAD
|
Dec. 31, 2016
EUR (€)
|
Dec. 31, 2015
USD ($)
|
Dec. 31, 2015
GBP (£)
|
Dec. 31, 2015
JPY (¥)
|
Dec. 31, 2015
CAD
|
Dec. 31, 2015
EUR (€)
|
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| Net Investment Hedges [Member] | CAD | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | $ 100,000,000 | CAD 133,000,000 | $ 0 | CAD 0 | $ 0 | CAD 0 | |||||||||||||||
| New contracts | 99,000,000 | 133,000,000 | 100,000,000 | 133,000,000 | 298,000,000 | 394,000,000 | |||||||||||||||
| Matured, expired or settled contracts | (100,000,000) | (133,000,000) | 0 | 0 | (298,000,000) | (394,000,000) | |||||||||||||||
| Notional amounts at December 31 | $ 99,000,000 | CAD 133,000,000 | 100,000,000 | 133,000,000 | 0 | CAD 0 | |||||||||||||||
| Weighted average forward rate at December 31 | CAD / $ | 1.34 | 1.34 | 1.34 | 1.34 | 1.34 | ||||||||||||||||
| Active contracts at December 31 | 2 | 2 | 2 | 2 | 2 | ||||||||||||||||
| Net Investment Hedges [Member] | GBP [Member] | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | $ 46,000,000 | £ 31,000,000 | 386,000,000 | £ 238,000,000 | 400,000,000 | £ 238,000,000 | |||||||||||||||
| New contracts | 127,000,000 | 100,000,000 | 131,000,000 | 90,000,000 | 186,000,000 | 118,000,000 | |||||||||||||||
| Matured, expired or settled contracts | (173,000,000) | (131,000,000) | (471,000,000) | (297,000,000) | (200,000,000) | (118,000,000) | |||||||||||||||
| Notional amounts at December 31 | $ 0 | £ 0 | 46,000,000 | 31,000,000 | 386,000,000 | 238,000,000 | |||||||||||||||
| Weighted average forward rate at December 31 | £ / $ | 0 | 0 | 0 | 0 | 0 | ||||||||||||||||
| Active contracts at December 31 | 0 | 0 | 0 | 0 | 0 | ||||||||||||||||
| Net Investment Hedges [Member] | JPY | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | $ 0 | ¥ 0 | 0 | ¥ 0 | 250,000,000 | ¥ 24,136,000,000 | |||||||||||||||
| New contracts | 99,000,000 | 11,189,000,000 | 353,000,000 | 43,373,000,000 | |||||||||||||||||
| Matured, expired or settled contracts | (99,000,000) | (11,189,000,000) | (603,000,000) | (67,509,000,000) | |||||||||||||||||
| Notional amounts at December 31 | 0 | 0 | 0 | 0 | |||||||||||||||||
| Net Investment Hedges [Member] | EUR | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | 0 | € 0 | 400,000,000 | € 300,000,000 | |||||||||||||||||
| New contracts | 0 | 0 | |||||||||||||||||||
| Matured, expired or settled contracts | (400,000,000) | (300,000,000) | |||||||||||||||||||
| Notional amounts at December 31 | 0 | 0 | |||||||||||||||||||
| Forwards and Options [Member] | CAD | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | 38,000,000 | [1] | CAD 50,000,000 | ||||||||||||||||||
| New contracts | 41,000,000 | [1] | 52,000,000 | ||||||||||||||||||
| Matured, expired or settled contracts | (23,000,000) | [1] | (30,000,000) | ||||||||||||||||||
| Notional amounts at December 31 | $ 56,000,000 | [1] | CAD 72,000,000 | 38,000,000 | [1] | CAD 50,000,000 | |||||||||||||||
| Weighted average forward rate at December 31 | CAD / $ | 1.29 | 1.29 | 1.29 | 1.29 | 1.29 | ||||||||||||||||
| Active contracts at December 31 | 24 | 24 | 24 | 24 | 24 | ||||||||||||||||
| Forwards and Options [Member] | GBP [Member] | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | $ 78,000,000 | [1] | £ 48,000,000 | 148,000,000 | [1] | 97,000,000 | 0 | [1] | 0 | ||||||||||||
| New contracts | 151,000,000 | [1] | 117,000,000 | 0 | [1] | 0 | 300,000,000 | [1] | 199,000,000 | ||||||||||||
| Matured, expired or settled contracts | (97,000,000) | [1] | (63,000,000) | (70,000,000) | [1] | (49,000,000) | (152,000,000) | [1] | (102,000,000) | ||||||||||||
| Notional amounts at December 31 | $ 132,000,000 | [1] | £ 102,000,000 | 78,000,000 | [1] | £ 48,000,000 | 148,000,000 | [1] | £ 97,000,000 | ||||||||||||
| Weighted average forward rate at December 31 | £ / $ | 1.29 | 1.29 | 1.29 | 1.29 | 1.29 | ||||||||||||||||
| Active contracts at December 31 | 20 | 20 | 20 | 20 | 20 | ||||||||||||||||
| Forwards and Options [Member] | JPY | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | $ 144,000,000 | [1] | ¥ 15,500,000,000 | 109,000,000 | [1] | 12,840,000,000 | 0 | [1] | 0 | ||||||||||||
| New contracts | 75,000,000 | [1] | 8,000,000,000 | 146,000,000 | [1] | 15,460,000,000 | 159,000,000 | [1] | 18,740,000,000 | ||||||||||||
| Matured, expired or settled contracts | (66,000,000) | [1] | (7,300,000,000) | (111,000,000) | [1] | (12,800,000,000) | (50,000,000) | [1] | (5,900,000,000) | ||||||||||||
| Notional amounts at December 31 | $ 153,000,000 | [1] | ¥ 16,200,000,000 | 144,000,000 | [1] | ¥ 15,500,000,000 | 109,000,000 | [1] | ¥ 12,840,000,000 | ||||||||||||
| Weighted average forward rate at December 31 | ¥ / $ | 106.25 | 106.25 | 106.25 | 106.25 | 106.25 | ||||||||||||||||
| Active contracts at December 31 | 34 | 34 | 34 | 34 | 34 | ||||||||||||||||
| Forwards and Options [Member] | USD [Member] | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | $ | [1] | $ 38,000,000 | 50,000,000 | 0 | |||||||||||||||||
| New contracts | $ | [1] | 15,000,000 | 71,000,000 | ||||||||||||||||||
| Matured, expired or settled contracts | $ | [1] | (27,000,000) | (21,000,000) | ||||||||||||||||||
| Notional amounts at December 31 | $ | [1] | 38,000,000 | 50,000,000 | ||||||||||||||||||
| Forwards and Options [Member] | EUR | |||||||||||||||||||||
| Derivative [Line Items] | |||||||||||||||||||||
| Notional amounts at January 1 | 197,000,000 | [1] | € 174,000,000 | 310,000,000 | [1] | 275,000,000 | 354,000,000 | [1] | 284,000,000 | ||||||||||||
| New contracts | 143,000,000 | [1] | 120,000,000 | 413,000,000 | [1] | 369,000,000 | 375,000,000 | [1] | 333,000,000 | ||||||||||||
| Matured, expired or settled contracts | (107,000,000) | [1] | (95,000,000) | (526,000,000) | [1] | (470,000,000) | (419,000,000) | [1] | (342,000,000) | ||||||||||||
| Notional amounts at December 31 | $ 233,000,000 | [1] | € 199,000,000 | $ 197,000,000 | [1] | € 174,000,000 | $ 310,000,000 | [1] | € 275,000,000 | ||||||||||||
| Weighted average forward rate at December 31 | € / $ | 1.17 | 1.17 | 1.17 | 1.17 | 1.17 | ||||||||||||||||
| Active contracts at December 31 | 29 | 29 | 29 | 29 | 29 | ||||||||||||||||
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