Acquisitions - Schedules of Loans Acquired (Details) $ in Millions	May 30, 2017 USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest payments	$ 49.7
Contractual cash flows not expected to be collected (non-accretable discount)	24.7
Cash flows expected to be collected	25.0
Interest component of cash flows expected to be collected (accretable discount)	1.9
Fair value of acquired credit-impaired loans	23.1
Contractually required principal and interest payments	2,098.1
Contractual cash flows not expected to be collected	23.3
Fair value at acquisition	$ 2,066.5