Goodwill and Other Intangible Assets - Summary of changes (Details) - USD ($) $ in Thousands		12 Months Ended
Apr. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Impairment of Goodwill	$ 0	$ 0
Goodwill
Goodwill, Beginning Balance		1,002,900	$ 999,586
PSC acquisition Day 1 adjustment			3,314
Goodwill, Ending Balance		$ 1,002,900	$ 1,002,900

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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