The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Business Combinations (Details) - USD ($)	12 Months Ended
Business Combinations (Details) - USD ($)	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill	$ 714,963,000	$ 714,963,000	$ 713,527,000	$ 681,358,000
2020 Acquisition
Business Acquisition [Line Items]
Gross Aggregate Consideration	110,200,000
Cash Assumed	1,700,000
Business Combination, Consideration Transferred	106,000,000.0
Business Combination indemnity holdback liability	2,500,000
Current Assets	54,800,000
Property, Plant, and Equipment	27,100,000
Goodwill	33,600,000
Other Intangibles	19,000,000.0
Current Liabilities	22,600,000
Deferred Credits and Other Liabilities	300,000
Asset Retirement Obligation	$ 1,400,000