Summary of Significant Accounting Policies - Impact of Recently Issued Accounting Standards (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019
Impact of Recently Issued Accounting Standards-Adopted
Operating lease right-of-use assets	$ 201.5
Operating lease liability	$ 202.0
Restated Amount | ASU 2016-02 Leases
Impact of Recently Issued Accounting Standards-Adopted
Operating lease right-of-use assets		$ 186.3
Operating lease liability		$ 187.1