Derivatives - Additional Information (Details) - USD ($)	Jun. 30, 2020	Mar. 31, 2019
Derivative [Line Items]
Notional amount		$ 250,000,000
Accumulated other comprehensive income (loss), be Reclassified During Next 12 Months	$ 14,000,000
Interest Rate Swaps A
Derivative [Line Items]
Notional amount	250,000,000
Interest Rate Swaps B
Derivative [Line Items]
Notional amount	250,000,000
Interest Rate Swap C
Derivative [Line Items]
Notional amount	250,000,000
Available-for-sale securities and interest rate swaps
Derivative [Line Items]
Accumulated other comprehensive loss, net of tax	$ (66,000,000)
LIBOR | Interest Rate Swaps A
Derivative [Line Items]
Fixed interest rate	3.04%
LIBOR | Interest Rate Swaps B
Derivative [Line Items]
Fixed interest rate	3.01%
LIBOR | Interest Rate Swap C
Derivative [Line Items]
Fixed interest rate	2.82%