Fair Value Measurements Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - Fair Value, Measurements, Recurring - Fair Value, Inputs, Level 3 - USD ($)	6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		$ 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value - Beginning	$ 433,000	403,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		(12,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value - Ending		391,000
Equity Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value - Beginning	433,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	2,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value - Ending	435,000
Other Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(18,000)	(20,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value - Beginning	181,000	192,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	(20,000)	(21,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value - Ending	$ 161,000	$ 171,000