Summary of Significant Accounting policies - Share Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
Dec. 31, 2020	Jun. 10, 2020
Summary of Significant Accounting Policies
Amount the company can repurchase		$ 50.0
Treasury Stock, Value, Acquired, Cost Method	$ 5.0
Treasury Stock, Shares, Acquired	0.3
Treasury Stock Acquired, Average Cost Per Share	$ 20.10

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

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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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section S99
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