v3.6.0.2

Investments - Average Coupon Rate Percentage and the Average Days to Maturity of Debt (Detail) | 12 Months Ended
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Dec. 31, 2016 | Dec. 31, 2015
Commercial Paper [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 1.001% | 0.553%
Average Days To Maturity | 184 days | 154 days
US Government Agencies [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 0.97% | 0.865%
Average Days To Maturity | 400 days | 599 days
Corporate Bonds and Notes [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 1.745% | 1.757%
Average Days To Maturity | 318 days | 331 days

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- Definition Average coupon rate. + References No definition available. + Details
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- Definition Average Term To Maturity + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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- Details
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