Goodwill and Other Intangible Assets - Narrative (Details) - Intangible Assets - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 26.2	$ 28.7	$ 27.6	$ 24.7	$ 25.8	$ 25.8	$ 25.0	$ 22.5	$ 107.2	$ 99.1	$ 100.1
Amortization of direct lease acquisition costs									$ 48.2	$ 43.2	$ 40.0
Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life									5 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life									40 years
Direct Lease Acquisition Cost | Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life									28 days
Direct Lease Acquisition Cost | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life									1 year