Business Combinations - Assets Acquired & Liabilities Assumed (Details 2) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill	$ 765,386,000	$ 714,963,000	$ 681,358,000
Asset Retirement Obligation	468,686,000	446,919,000	$ 417,575,000
2020 Acquisition [Member]
Business Acquisition [Line Items]
Gross Aggregate Consideration		110,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		1,700,000
Business Combination, Consideration Transferred		106,000,000
Business Combination, Consideration Transferred, Liabilities Incurred	$ 2,500,000	2,500,000
Business Combination, Current Assets		54,800,000
Business Combination, Property, Plant, and Equipment		27,100,000
Goodwill		33,600,000
Business Combination, Other Intangible Assets		19,000,000
Business Combination, Current Liabilities		22,600,000
Business Combination, Noncurrent Liabilities		300,000
Asset Retirement Obligation		$ 1,400,000