Summary of Significant Accounting Policies - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Operating Leases
Operating lease right-of-use assets	$ 126.8
Other accrued liabilities	69.2
Long-term operating lease liabilities	83.8
Total operating lease liabilities	153.0
Finance Leases
Outsourcing assets, net	5.0
Current maturities of long-term debt	1.7
Long-term debt	4.0
Total finance lease liabilities	$ 5.7	$ 5.8
Weighted-Average Remaining Lease Term
Operating leases	3 years 2 months 12 days
Finance leases	3 years 2 months 12 days
Weighted-Average Discount Rate
Operating leases	6.30%
Finance leases	4.90%