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Stockholders' Equity - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015
Class of Stock [Line Items] |  |  |  |  |  |
Common stock dividend paid | $ 0.16 | $ 0.16 | $ 0.16 | $ 0.16 | $ 0.48 | $ 0.48
Purchase price of common stock repurchased on open market | $ 200,000,000 |  |  | $ 175,000,000 | $ 575,000,000 | $ 775,000,000
Authorized share repurchased program remaining available amount | $ 180,000,000 |  |  |  | $ 180,000,000 |
Common Stock [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Closing price of common stock | $ 14.47 |  |  |  | $ 14.47 |
Common Stock Shares Outstanding [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Common shares repurchased | 14,347,974 |  |  | 12,075,388 | 47,137,636 | 41,919,908

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