Debt (Notes)	3 Months Ended
Sep. 30, 2018
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	DEBT Revolving Credit Facility & Term Loan In January 2018, in conjunction with the acquisition of FCX, the Company refinanced its existing credit facility and entered into a new five-year credit facility with a group of banks expiring in January 2023. This agreement provides for a $780,000 unsecured term loan and a $250,000 unsecured revolving credit facility. Fees on this facility range from 0.10% to 0.20% per year based upon the Company's leverage ratio at each quarter end. Borrowings under this agreement carry variable interest rates tied to either LIBOR or prime at the Company's discretion. At September 30, 2018 and June 30, 2018, the Company had $628,250 and $775,125, respectively, outstanding under the term loan. The interest rate on the term loan as of September 30, 2018 and June 30, 2018 was 4.25% and 4.13%, respectively. The Company had no amount outstanding under the revolver at September 30, 2018, and $19,500 was outstanding under the revolver at June 30, 2018. Unused lines under this facility, net of outstanding letters of credit of $4,573 and $3,625, respectively, to secure certain insurance obligations, totaled $245,427 and $226,875 at September 30, 2018 and June 30, 2018, respectively, and were available to fund future acquisitions or other capital and operating requirements. The weighted average interest rate on the amount outstanding under the revolving credit facility as of June 30, 2018 was 3.93%. Additionally, the Company had letters of credit outstanding with a separate bank, not associated with the revolving credit agreement, in the amount of $2,698 as of September 30, 2018 and June 30, 2018, in order to secure certain insurance obligations. Trade Receivable Securitization Facility In August 2018, the Company established a trade receivable securitization facility (the “AR Securitization Facility”) with a termination date of August 31, 2021. The maximum availability under the AR Securitization Facility is $175,000. Availability is further subject to changes in the credit ratings of our customers, customer concentration levels or certain characteristics of the accounts receivable being transferred and, therefore, at certain times, we may not be able to fully access the $175,000 of funding available under the AR Securitization Facility. The AR Securitization Facility effectively increases the Company’s borrowing capacity by collateralizing a portion of the amount of the Service Center Based Distribution reportable segment’s U.S. operations’ trade accounts receivable. The collateralized trade accounts receivable is equal to the borrowed amount outstanding under the AR Securitization Facility and there were no restrictions on cash or other assets. The Company uses the proceeds from the AR Securitization Facility as an alternative to other forms of debt, effectively reducing borrowing costs. Borrowings under this facility carry variable interest rates tied to LIBOR and fees on the AR Securitization Facility are 0.90% per year. As of September 30, 2018, the Company has borrowed $175,000 under the AR Securitization Facility, and the interest rate was 2.08%. Other Long-Term Borrowings At September 30, 2018 and June 30, 2018, the Company had borrowings outstanding under its unsecured shelf facility agreement with Prudential Investment Management of $170,000. The "Series C" notes have a principal amount of $120,000 and carry a fixed interest rate of 3.19%, and are due in equal principal payments in July 2020, 2021, and 2022. The "Series D" notes have a principal amount of $50,000 and carry a fixed interest rate of 3.21%, and are due in equal principal payments in October 2019 and 2023. As of September 30, 2018, $50,000 in additional financing was available under this facility. In April 2014 the Company assumed $2,359 of debt as a part of the headquarters facility acquisition. The 1.5% fixed interest rate note is held by the State of Ohio Development Services Agency, maturing in May 2024. At September 30, 2018 and June 30, 2018, $1,380 and $1,438 was outstanding, respectively. Unamortized debt issue costs of $551 are included as a reduction of current portion of long-term debt on the condensed consolidated balance sheets as of September 30, 2018 and June 30, 2018, respectively. Unamortized debt issue costs of $1,679 and $1,807 are included as a reduction of long-term debt on the condensed consolidated balance sheets as of September 30, 2018 and June 30, 2018, respectively.

DEBT

Revolving Credit Facility & Term Loan

In January 2018, in conjunction with the acquisition of FCX, the Company refinanced its existing credit facility and entered into a new five-year credit facility with a group of banks expiring in January 2023. This agreement provides for a $780,000 unsecured term loan and a $250,000 unsecured revolving credit facility. Fees on this facility range from 0.10% to 0.20% per year based upon the Company's leverage ratio at each quarter end. Borrowings under this agreement carry variable interest rates tied to either LIBOR or prime at the Company's discretion. At September 30, 2018 and June 30, 2018, the Company had $628,250 and $775,125, respectively, outstanding under the term loan. The interest rate on the term loan as of September 30, 2018 and June 30, 2018 was 4.25% and 4.13%, respectively. The Company had no amount outstanding under the revolver at September 30, 2018, and $19,500 was outstanding under the revolver at June 30, 2018. Unused lines under this facility, net of outstanding letters of credit of $4,573 and $3,625, respectively, to secure certain insurance obligations, totaled $245,427 and $226,875 at September 30, 2018 and June 30, 2018, respectively, and were available to fund future acquisitions or other capital and operating requirements. The weighted average interest rate on the amount outstanding under the revolving credit facility as of June 30, 2018 was 3.93%.

Additionally, the Company had letters of credit outstanding with a separate bank, not associated with the revolving credit agreement, in the amount of $2,698 as of September 30, 2018 and June 30, 2018, in order to secure certain insurance obligations.

Trade Receivable Securitization Facility

In August 2018, the Company established a trade receivable securitization facility (the “AR Securitization Facility”) with a termination date of August 31, 2021. The maximum availability under the AR Securitization Facility is $175,000. Availability is further subject to changes in the credit ratings of our customers, customer concentration levels or certain characteristics of the accounts receivable being transferred and, therefore, at certain times, we may not be able to fully access the $175,000 of funding available under the AR Securitization Facility. The AR Securitization Facility effectively increases the Company’s borrowing capacity by collateralizing a portion of the amount of the Service Center Based Distribution reportable segment’s U.S. operations’ trade accounts receivable. The collateralized trade accounts receivable is equal to the borrowed amount outstanding under the AR Securitization Facility and there were no restrictions on cash or other assets. The Company uses the proceeds from the AR Securitization Facility as an alternative to other forms of debt, effectively reducing borrowing costs. Borrowings under this facility carry variable interest rates tied to LIBOR and fees on the AR Securitization Facility are 0.90% per year. As of September 30, 2018, the Company has borrowed $175,000 under the AR Securitization Facility, and the interest rate was 2.08%.

Other Long-Term Borrowings

At September 30, 2018 and June 30, 2018, the Company had borrowings outstanding under its unsecured shelf facility agreement with Prudential Investment Management of $170,000. The "Series C" notes have a principal amount of $120,000 and carry a fixed interest rate of 3.19%, and are due in equal principal payments in July 2020, 2021, and 2022. The "Series D" notes have a principal amount of $50,000 and carry a fixed interest rate of 3.21%, and are due in equal principal payments in October 2019 and 2023. As of September 30, 2018, $50,000 in additional financing was available under this facility.

In April 2014 the Company assumed $2,359 of debt as a part of the headquarters facility acquisition. The 1.5% fixed interest rate note is held by the State of Ohio Development Services Agency, maturing in May 2024. At September 30, 2018 and June 30, 2018, $1,380 and $1,438 was outstanding, respectively.

Unamortized debt issue costs of $551 are included as a reduction of current portion of long-term debt on the condensed consolidated balance sheets as of September 30, 2018 and June 30, 2018, respectively. Unamortized debt issue costs of $1,679 and $1,807 are included as a reduction of long-term debt on the condensed consolidated balance sheets as of September 30, 2018 and June 30, 2018, respectively.