Derivatives - FV of Derivatives on the Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives fair value	$ 9,102	$ 17,436
Liability derivatives fair value	2,414	228
Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Asset derivatives fair value	6,485	4,062
Liability derivatives fair value	6,169	3,893
Other assets [Member] | Interest rate products [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives fair value	9,102	17,436
Other assets [Member] | Interest rate products [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Asset derivatives fair value	4,933	3,191
Other assets [Member] | Interest Rate Lock Commitments [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Asset derivatives fair value	1,539	871
Other assets [Member] | Forward Contracts [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Asset derivatives fair value	13
Other liabilities [Member] | Interest rate products [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives fair value	2,414	228
Other liabilities [Member] | Interest rate products [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Liability derivatives fair value	5,358	3,349
Other liabilities [Member] | Interest Rate Lock Commitments [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Liability derivatives fair value	110	72
Other liabilities [Member] | Forward Contracts [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Liability derivatives fair value	$ 701	$ 472