Loans - Schedule of Allowance for Credit Losses for Loans Held for Investment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 73.0	$ 73.0
Provision for Credit Loss Expense	29.0	3.7
Loans Charged-Off	(4.6)	(6.0)
Recoveries Collected		1.7
Ending balance	$ 129.1	72.4
Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		31.0
Provision for Credit Loss Expense		1.7
Loans Charged-Off		(2.1)
Recoveries Collected		0.2
Ending balance		27.4
Total consumer loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		8.7
Provision for Credit Loss Expense		2.0
Loans Charged-Off		(3.0)
Recoveries Collected		1.1
Ending balance		8.8
Commercial
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		31.3
Provision for Credit Loss Expense		3.6
Loans Charged-Off		(0.8)
Recoveries Collected		0.4
Ending balance		34.5
Agricultural
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		2.0
Provision for Credit Loss Expense		0.2
Loans Charged-Off		(0.1)
Recoveries Collected		0.0
Ending balance		$ 1.7