Segment Information - Reconciliation of Total Segment Profit to Income before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Reconciliation to Income before Income Taxes
Total segment profit for reportable segments	$ 41,659	$ 63,758	$ 88,963	$ 100,748
General and administrative	(16,422)	(15,299)	(36,306)	(31,383)
Interest income	8,428	7,485	16,404	14,554
Interest Expense	3,161	2,164	6,161	3,978
Other (expense) income, net	(997)	(578)	135	(451)
Income before income taxes	45,929	68,501	99,341	110,873
Operating segments
Reconciliation to Income before Income Taxes
Total segment profit for reportable segments	58,081	79,057	125,269	132,131
Segment Reconciling Items
Reconciliation to Income before Income Taxes
General and administrative	(16,422)	(15,299)	(36,306)	(31,383)
Interest income	8,428	7,485	16,404	14,554
Interest Expense	(3,161)	(2,164)	(6,161)	(3,978)
Other (expense) income, net	$ (997)	$ (578)	$ 135	$ (451)