Share Transactions - Share repurchase program (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2020	Jun. 30, 2020
Share Transactions [Abstract]
Authorized amount of share repurchase program	$ 50.0
Number of shares repurchased	127,744
Shares repurchased, average cost per share	$ 22.42
Remaining authorized repurchase amount		$ 47.1
Number of shares acquired since inception		2,900,000
Shares repurchased, value		$ 77.9

Amount of stock repurchase plan authorized.

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-Topic 505
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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
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-Section 45
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-Topic 505
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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- Definition

Share Transactions [Abstract]

+ References

No definition available.

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- Definition

Cumulative number of shares that have been repurchased since the inception of the share repurchase program.

+ References

No definition available.

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