On March 27, 2019, the Company entered into an amended and restated credit agreement (the “Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank, that extends the term of the Company’s existing $850,000,000 revolving credit facility (“Revolving Credit Facility”) to March 27, 2024 and adds a five-year term loan (“Term Loan”) facility in an amount of $500,000,000. The Credit Agreement provides for a variable interest rate based on the London interbank offered rate (“LIBOR”) or a base rate calculated with reference to the agent bank’s prime rate, among other factors (the “Alternate Base Rate”). The interest rate varies with the Company’s credit rating and is currently 112.5 basis points over LIBOR or 12.5 basis points over the Alternate Base Rate. The Term Loan is repayable in quarterly installments commencing June 30, 2020, in increasing percentages of the original principal amount of the loan, with the remaining unpaid balance payable of 65% of the initial amount due on March 27, 2024. The Credit Agreement contains certain financial covenants including an interest coverage ratio and a debt-to-capitalization ratio. In addition to financial covenants, the Credit Agreement contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates and changes in lines of business. The Credit Agreement specifies certain events of default, upon the occurrence of which the maturity of the outstanding loans may be accelerated, including the failure to pay principal or interest, violation of covenants and default on other indebtedness, among other events. Borrowings under the Credit Agreement may be used for general corporate purposes including acquisitions. As of June 30, 2019, the Company was in compliance with all Credit Agreement covenants and had outstanding borrowings of $103,577,000 under the Revolving Credit Facility and $500,000,000 under the Term Loan. The Revolving Credit Facility includes a $25,000,000 commitment which may be used for standby letters of credit. Outstanding letters of credit under the Revolving Credit Facility were $5,670,000 as of June 30, 2019.

LONG-TERM DEBT	6 Months Ended
Jun. 30, 2019
LONG-TERM DEBT [Abstract]
LONG-TERM DEBT	(7) LONG-TERM DEBT On March 27, 2019, the Company entered into an amended and restated credit agreement (the “Credit Agreement”) with a group of commercial banks, with JPMorgan Chase Bank, N.A. as the administrative agent bank, that extends the term of the Company’s existing $850,000,000 revolving credit facility (“Revolving Credit Facility”) to March 27, 2024 and adds a five-year term loan (“Term Loan”) facility in an amount of $500,000,000. The Credit Agreement provides for a variable interest rate based on the London interbank offered rate (“LIBOR”) or a base rate calculated with reference to the agent bank’s prime rate, among other factors (the “Alternate Base Rate”). The interest rate varies with the Company’s credit rating and is currently 112.5 basis points over LIBOR or 12.5 basis points over the Alternate Base Rate. The Term Loan is repayable in quarterly installments commencing June 30, 2020, in increasing percentages of the original principal amount of the loan, with the remaining unpaid balance payable of 65% of the initial amount due on March 27, 2024. The Credit Agreement contains certain financial covenants including an interest coverage ratio and a debt-to-capitalization ratio. In addition to financial covenants, the Credit Agreement contains covenants that, subject to exceptions, restrict debt incurrence, mergers and acquisitions, sales of assets, dividends and investments, liquidations and dissolutions, capital leases, transactions with affiliates and changes in lines of business. The Credit Agreement specifies certain events of default, upon the occurrence of which the maturity of the outstanding loans may be accelerated, including the failure to pay principal or interest, violation of covenants and default on other indebtedness, among other events. Borrowings under the Credit Agreement may be used for general corporate purposes including acquisitions. As of June 30, 2019, the Company was in compliance with all Credit Agreement covenants and had outstanding borrowings of $103,577,000 under the Revolving Credit Facility and $500,000,000 under the Term Loan. The Revolving Credit Facility includes a $25,000,000 commitment which may be used for standby letters of credit. Outstanding letters of credit under the Revolving Credit Facility were $5,670,000 as of June 30, 2019. The estimated fair value of total debt outstanding at June 30, 2019 and December 31, 2018 was $1,637,493,000 and $1,411,628,000, respectively, which differs from the carrying amounts of $1,594,706,000 and $1,410,188,000, respectively, included in the consolidated financial statements. The fair value of debt outstanding was determined using a Level 2 fair value measurement.