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Stockholders' Equity - Additional Information (Details) - USD ($) | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019 | Mar. 13, 2020 | Nov. 30, 2014
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |
Cash dividends declared per common share (usd per share) |  | $ 0.08 | $ 0.08 | $ 0.08 | $ 0.08 | $ 0.24 | $ 0.24 |  |
Payments of common stock dividends |  | $ 4,800,000 | $ 4,900,000 | $ 4,800,000 | $ 4,900,000 | $ 14,500,000 | $ 14,500,000 |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |
Number of shares repurchased |  | 7,227 |  |  |  | 498,217 | 48,409 |  |
Treasury stock purchases |  | $ 200,000 |  |  |  | $ 13,700,000 | $ 1,000,000.0 |  |
Subsequent Event |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |
Cash dividends declared per common share (usd per share) | $ 0.08 |  |  |  |  |  |  |  |
November 2014 Repurchase Program |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |
Stock repurchase program, authorized amount |  |  |  |  |  |  |  |  | $ 75,000,000.0
March 2020 Repurchase Program |  |  |  |  |  |  |  |  |
Equity, Class of Treasury Stock [Line Items] |  |  |  |  |  |  |  |  |
Stock repurchase program, authorized amount |  |  |  |  |  |  |  | $ 75,000,000.0 |

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