Fair Value Measurements (Book Value and Estimated Fair Value) (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Apr. 01, 2017
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Servicing Asset at Fair Value, Amount		$ 1,310	$ 1,110
Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, Fair Value Disclosure	[1]	27,713	24,162
Non-marketable equity investments, Fair Value Disclosure	[2]	18,543	17,383
Notes Receivable, Fair Value Disclosure	[3]	97,501	95,801
Interest Rate Lock Commitments Fair Value Disclosure	[4]	21	35
Forward Commitments Fair Value Disclosure	[4]	159	(86)
Inventory Finance Receivable	[5]	31,156	25,833
Securitized Financings	[6]	(59,023)	(57,991)
Servicing Asset at Fair Value, Amount	[7]	1,310	1,110
Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Investments, Fair Value Disclosure	[1]	27,713	24,162
Non-marketable equity investments, Fair Value Disclosure	[2]	18,543	17,383
Notes Receivable, Fair Value Disclosure	[3]	122,711	121,021
Interest Rate Lock Commitments Fair Value Disclosure	[4]	21	35
Forward Commitments Fair Value Disclosure	[4]	159	(86)
Inventory Finance Receivable	[5]	31,249	25,841
Securitized Financings	[6]	(64,460)	(61,270)
Servicing Asset at Fair Value, Amount	[7]	1,310	$ 1,110
Fair Value, Measurements, Nonrecurring [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Securitized Financings		(64,460)
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Inventory Finance Receivable		0
Securitized Financings		0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Inventory Finance Receivable		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Inventory Finance Receivable		31,249
Securitized Financings		0
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Inventory Finance Receivable		$ 31,249

[1] the fair value is based on quoted market prices. The fair value of Level 2 securities is based on other inputs, as further described below.

[2] The fair value approximates book value based on the non-marketable nature of the investments.

[3] Includes consumer loans receivable held for investment, held for sale and construction advances. The fair value of the loans held for investment is based on the discounted value of the remaining principal and interest cash flows. The fair value of the loans held for sale are estimated based on recent GSE mortgage-backed bond prices. The fair value of the construction advances approximates book value and the sales price of these loans is estimated based on construction completed.

[4] The fair values are based on changes in GSE mortgage-backed bond prices and, additionally for IRLCs, pull through rates.

[5] The fair value is estimated using market interest rates of comparable loans.

[6] The fair value is estimated using recent public transactions of similar asset-backed securities.

[7] The fair value of the mortgage servicing rights is based on the present value of expected net cash flows related to servicing these loans.