Capital (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Mar. 16, 2018 |
Mar. 16, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
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| Class of Stock [Line Items] | ||||||
| Payments of dividends | $ 31.7 | $ 10.7 | ||||
| Dividend paid per sub-share (in usd per share) | $ 0 | $ 0 | $ 4.05 | $ 1.35 | ||
| Certificate | ||||||
| Class of Stock [Line Items] | ||||||
| Number of shares used in ratio (in shares) | 1 | |||||
| Sub Shares | ||||||
| Class of Stock [Line Items] | ||||||
| Number of shares used in ratio (in shares) | 3,000 | |||||
| Number of shares repurchased and retired (in shares) | 29,062 | 68,760 | ||||
| Cash Dividend | Sub Shares | ||||||
| Class of Stock [Line Items] | ||||||
| Dividend paid per sub-share (in usd per share) | $ 1.05 | $ 0.35 | ||||
| Special Dividend | Sub Shares | ||||||
| Class of Stock [Line Items] | ||||||
| Dividend paid per sub-share (in usd per share) | $ 3 | $ 1.00 | ||||
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- Definition The number of shares that are used in the ratio. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Aggregate dividends paid during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Number of shares that have been repurchased and retired during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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