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Stockholders' Equity - Common Share Repurchases and Issuances (Detail) - $ / shares | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Equity, Class of Treasury Stock [Line Items] |  |  |  |
Average purchase price per share | $ 13.06 |  | $ 12.24 |
Shares repurchased related to employee stock-based compensation plans | 120,485 | 92,369 | 2,534,090 | 3,557,504
Average purchase price per share | $ 13.45 | $ 14.53 | $ 10.94 | $ 13.77
Common shares issued | 195,883 | 113,171 | 4,625,347 | 5,134,238
Common Stock Shares Outstanding [Member] |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |
Common stock repurchased | 9,617,008 |  | 19,034,252 | 0
Shares repurchased related to employee stock-based compensation plans | 120,485 | 92,369 | 2,534,090 | 3,557,504
Common shares issued | 195,883 | 113,171 | 4,625,347 | 5,134,238

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- Definition For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer. + References No definition available. + Details
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