v3.5.0.2

Investments - Average Coupon Rate Percentage and the Average Days to Maturity of Debt (Detail) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2016 | Dec. 31, 2015
Commercial Paper [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 0.978% | 0.553%
Average Days To Maturity | 253 days | 154 days
US Government Agencies [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 0.979% | 0.865%
Average Days To Maturity | 512 days | 599 days
Corporate Bonds and Notes [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Average Coupon Rate | 1.643% | 1.757%
Average Days To Maturity | 330 days | 331 days

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