Fair Value Measurements Fair Value Measurements-Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($)		12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs, Recurring Basis, Asset, Transfers, Net		$ 0
Fair Value, Measurements, Recurring [Member] | Other investments | Fair Value, Inputs, Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		403,000	$ 193,000
Fair Value, Measurement with Unobservable Inputs, Recurring Basis, Asset, Gain (Loss) Included in Earnings		30,000	(1,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances		0	211,000
Fair Value, Measurement with Unobservable Inputs, Recurring Basis, Asset, Transfers, Net		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		433,000	403,000
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		0	0
Fair Value, Measurements, Recurring [Member] | Other Assets | Fair Value, Inputs, Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		192,000	201,000
Fair Value, Measurement with Unobservable Inputs, Recurring Basis, Asset, Gain (Loss) Included in Earnings	[1]	(11,000)	(9,000)
Fair Value, Measurement with Unobservable Inputs, Recurring Basis, Asset, Issuances, (Settlements)		0	0
Fair Value, Measurement with Unobservable Inputs, Recurring Basis, Asset, Transfers, Net		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		181,000	192,000
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		$ (10,000)	$ (9,000)

[1] (1) Includes net servicing cash flows and the passage of time.