Derivatives (Narratives) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021	Mar. 31, 2021
AOCI Attributable To Parent [Abstract]
Interest expense	$ 44,042	$ 42,128	$ 122,765	$ 122,174
Derivative Fair Value Of Derivative Net [Abstract]
Derivative hedges, net market value	0		0			$ 0
Decrease, fair value, cash flow hedges
AOCI Attributable To Parent [Abstract]
Interest expense			100
Reclassified AOCI
AOCI Attributable To Parent [Abstract]
Interest expense			2,300
Interest rate contracts
AOCI Attributable To Parent [Abstract]
Interest expense			2,300
Investments, other
Derivative Fair Value Of Derivative Net [Abstract]
Derivative hedges, net market value	6,600		6,600		$ 6,600
Derivative hedges, notional amount	$ 282,700		$ 282,700		$ 399,100