Stockholders' Equity - Additional Information (Detail) - USD ($) |
Mar. 31, 2016 |
Sep. 16, 2013 |
|---|---|---|
| Share Repurchases [Line Items] | ||
| Amount available for repurchase under the current share repurchase program approved by the company's Board of Directors | $ 40,000,000,000 | |
| Unused amount of share repurchase program | $ 10,700,000,000 |