v3.7.0.1

Investments - Average Coupon Rate Percentage and the Average Days to Maturity of Debt (Detail) | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2017 | Dec. 31, 2016
Commercial Paper [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 98.50% | 100.10%
Average Days To Maturity | 83 days | 184 days
US Government Agencies [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 105.60% | 97.00%
Average Days To Maturity | 264 days | 400 days
Corporate Bonds and Notes [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 172.00% | 174.50%
Average Days To Maturity | 246 days | 318 days

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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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