Equity - Accumulated Other Comprehensive Income Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
AOCI, Net of Tax
Beginning balance	$ 1,390,985	$ 891,719	$ 1,399,879	$ 648,822
Changes in unrealized gains	0	0	4,028	0
Realized (gains) losses reclassified to earnings	(120)	87	(217)	251
Ending balance	1,652,595	1,268,589	1,652,595	1,268,589
Total
AOCI, Net of Tax
Beginning balance	3,906	(1,746)	(25)	(1,910)
Ending balance	3,786	(1,659)	3,786	(1,659)
Unrealized Gains on Derivative Hedges
AOCI, Net of Tax
Beginning balance	5,506	1,918	1,718	2,130
Changes in unrealized gains	0	0	4,028	0
Realized (gains) losses reclassified to earnings	(192)	(101)	(432)	(313)
Ending balance	5,314	1,817	5,314	1,817
Unrealized Losses on Defined Benefit Plans
AOCI, Net of Tax
Beginning balance	(1,600)	(3,664)	(1,743)	(4,040)
Changes in unrealized gains	0	0	0	0
Realized (gains) losses reclassified to earnings	72	188	215	564
Ending balance	$ (1,528)	$ (3,476)	$ (1,528)	$ (3,476)