Receivables - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Delinquent FHA or VA Insured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for losses related to defaulted FHA or VA insured loans	$ 52.5	$ 53.3

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant