Significant Accounting Policies and Practices - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) partnership variable_interest_entity voting_interest_model_entity	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Significant Accounting Policies and Practices
Restricted cash and cash equivalents	$ 0.5		$ 0.5		$ 0.3
Number of ownership interest entities | partnership			31
Equity earnings in related investments	$ 0.3	$ 0.2	$ 0.4	$ 0.8
ASU 2021-01
Significant Accounting Policies and Practices
Change in accounting principle, accounting standards update, adopted [true false]	true		true
Change in accounting principle, accounting standards update, immaterial effect	true		true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020		Jan. 01, 2020
ASU 2020-10
Significant Accounting Policies and Practices
Change in accounting principle, accounting standards update, adopted [true false]	true		true
Change in accounting principle, accounting standards update, immaterial effect	true		true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020		Jan. 01, 2020
ASU 2020-03
Significant Accounting Policies and Practices
Change in accounting principle, accounting standards update, adopted [true false]	true		true
Change in accounting principle, accounting standards update, immaterial effect	true		true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020		Jan. 01, 2020
ASU 2019-11
Significant Accounting Policies and Practices
Change in accounting principle, accounting standards update, adopted [true false]	true		true
Change in accounting principle, accounting standards update, immaterial effect	true		true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2020		Jan. 01, 2020
Minimum
Significant Accounting Policies and Practices
Ownership interests percentage	30.00%		30.00%
Maximum
Significant Accounting Policies and Practices
Ownership interests percentage	50.00%		50.00%
Primary Beneficiary
Significant Accounting Policies and Practices
Number of ownership interest entities | variable_interest_entity			26
Not Primary Beneficiary
Significant Accounting Policies and Practices
Number of ownership interest entities | voting_interest_model_entity			5