Leases - ROU Assets and Lease Liabilities (Details) $ in Millions	Mar. 31, 2020 USD ($)
ROU assets:
Operating lease ROU assets	$ 431.8
Finance lease ROU assets	54.0
Total ROU assets	485.8
Lease liabilities:
Operating lease liabilities - current	86.5
Operating lease liabilities - noncurrent	351.8
Finance lease liabilities - current	6.2
Finance lease liabilities - noncurrent	41.4
Total lease liabilities	$ 485.9