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

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Percentage of principal amount of debt redeemed.

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Amount, after accumulated amortization, of debt discount.

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Borrowings (Details) $ / shares in Units, $ in Thousands	3 Months Ended
Borrowings (Details) $ / shares in Units, $ in Thousands	Sep. 30, 2019 USD ($) item $ / shares	Sep. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Feb. 28, 2017 USD ($)
Borrowings
Borrowings outstanding	$ 95,000		$ 88,000
Number of consecutive trading days \| item	30
Components of long-term debt
Other long-term debt	$ 2,004		2,061
Total	260,808		258,556
Less current portion of long-term debt	(801)		(804)
Long-term portion of debt	260,007		257,752
Revolving Credit Facility
Borrowings
Maximum borrowing capacity	535,000
Sub-limit available for letters of credit	$ 300,000
Unused commitment fee (as a percent)	0.10%
Borrowings outstanding	$ 95,000
Amount outstanding under letters of credit	49,400
Available credit facility	$ 390,600
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%
1.25% Convertible Senior Notes Due 2022
Borrowings
Principal amount	$ 287,500			$ 287,500
Interest rate (as a percentage)	1.25%			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 \| item	20
Number of consecutive trading days \| item	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	3,200	$ 3,100
Contractual interest expense	900	900
Amortization of debt discount	2,000	1,900
Amortization of debt issuance costs	300	$ 300
Unamortized discount	$ (25,268)		(27,283)
Effective interest rate (as a percent)	4.50%
Unamortized debt issuance costs	$ 3,428		3,722
Components of long-term debt
Principal amount	287,500		287,500
Unamortized discount	(25,268)		(27,283)
Unamortized debt issuance costs	(3,428)		(3,722)
Total	258,804		$ 256,495
Bank lines of credit
Borrowings
Amount outstanding under letters of credit	44,200
Available credit facility	$ 20,900