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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Face (par) amount of debt instrument at time of issuance.

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Percentage of principal amount of debt redeemed.

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Borrowings (Details) $ / shares in Units, $ in Thousands	3 Months Ended
Borrowings (Details) $ / shares in Units, $ in Thousands	Sep. 30, 2021 USD ($) D $ / shares	Sep. 30, 2020 USD ($)	Jul. 01, 2021 USD ($)	Jun. 30, 2021 USD ($)	Feb. 28, 2017 USD ($)
Borrowings
Borrowings outstanding	$ 26,000
Increase to retained earnings	586,850			$ 548,842
Reduction in common stock	53,377			105,724
Revolving Credit Facility
Borrowings
Maximum borrowing capacity	$ 535,000
Unused commitment fee (as a percent)	0.10%
Borrowings outstanding	$ 26,000
Available credit facility	$ 429,600
Revolving Credit Facility \| Minimum
Borrowings
Unused commitment fee (as a percent)	0.10%
Revolving Credit Facility \| Maximum
Borrowings
Increase in the credit agreement's borrowing capacity available under certain circumstances	$ 250,000
Unused commitment fee (as a percent)	0.25%
Revolving Credit Facility \| LIBOR
Borrowings
Interest rate margin (as a percent)	1.00%
Revolving Credit Facility \| LIBOR \| Minimum
Borrowings
Interest rate margin (as a percent)	1.00%
Revolving Credit Facility \| LIBOR \| Maximum
Borrowings
Interest rate margin (as a percent)	1.75%
Letters of credit sub facility
Borrowings
Maximum borrowing capacity	$ 300,000
Amount outstanding under letters of credit	79,400
1.25% Convertible Senior Notes Due 2022
Borrowings
Principal amount	$ 287,500				$ 287,500
Interest rate (as a percentage)	1.25%
Conversion ratio	9.3056
Conversion price \| $ / shares	$ 107.46
Premium on stock price	38.50%
Threshold percentage of stock price	130.00%
Number of trading days \| D	20
Number of consecutive trading days \| D	30
Principal amount of the notes to be repurchased (as a percentage)	100.00%
Liability component of convertible debt	$ 242,400
Equity component of convertible debt	45,100
Debt issuance costs	7,700
Debt Component of debt issuance costs	6,500
Equity component of debt issuance costs	1,200
Total interest expense	1,200	$ 3,300
Contractual interest expense	900	900
Amortization of debt discount		2,100
Amortization of debt issuance costs	300	$ 300
Unamortized discount				10,494
Unamortized debt issuance costs	1,300			$ 1,400
Bank lines of credit
Borrowings
Amount outstanding under letters of credit	65,700
Available credit facility	$ 9,400
ASU 2020-06 \| Cumulative effect period of adoption, adjustment
Borrowings
Liability component of convertible debt			$ 10,000
Increase to retained earnings			19,000
Reduction in common stock			27,000
ASU 2020-06 \| Cumulative effect period of adoption, adjustment \| 1.25% Convertible Senior Notes Due 2022
Borrowings
Liability component of convertible debt			10,000
Increase to retained earnings			19,000
Reduction in common stock			$ 27,000