Fair Value Measurements Information About Fair Value Measurements Using Significant Unobservable Inputs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012
Securitized Beneficial Interests [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Fair Value of Unobservable Inputs	25,864
Guarantees of Farmers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Fair Value of Unobservable Inputs	4,496
Guarantees of Unconsolidated Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Fair Value of Unobservable Inputs	769
Historical Loss Valuation Technique [Member] | Minimum [Member] | Guarantees of Farmers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable Input, Historical Loss	6.00%
Historical Loss Valuation Technique [Member] | Maximum [Member] | Guarantees of Farmers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable Input, Historical Loss	7.80%
Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Securitized Beneficial Interests [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable Input, Securitized Market Rate	2.52%
Unobservable Input, Payment Speed	91 days
Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Guarantees of Unconsolidated Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable Input, Market Interest Rate	9.00%
Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Securitized Beneficial Interests [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable Input, Securitized Market Rate	3.78%
Unobservable Input, Payment Speed	133 days
Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Guarantees of Unconsolidated Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Unobservable Input, Market Interest Rate	14.00%