Loans Receivable (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Age of Consumer Loans contractual payments due with no forecasted future net cash flows	120 months
Impact of Forecast Change on Credit Losses	$ 41.6
Impact of Forecast Change on Finance Charges	7.3
Impact of Forecast Change on Net Income	$ 30.8
Decrease in Forecated Net Cash Flows		$ 1.8