Revolving Line of Credit	3 Months Ended
Dec. 31, 2017
Debt Disclosure [Abstract]
Revolving Line of Credit	Revolving Line of Credit On November 17, 2017, we amended our credit agreement with a syndicate of banks, increasing our borrowing capacity under the unsecured revolving line of credit to $600 million. The revolving line of credit expires on December 30, 2019. Proceeds from the credit facility can be used for working capital and general corporate purposes and may also be used for the refinancing of existing debt, acquisitions and the repurchase of our common stock. Interest on amounts borrowed under the credit facility is based on (i) a base rate, which is the greater of (a) the prime rate, (b) the Federal Funds rate plus 0.500% and (c) the one-month LIBOR rate plus 1.000%, plus, in each case, an applicable margin, or (ii) an adjusted LIBOR rate plus an applicable margin. The applicable margin for base rate borrowings ranges from 0% to 0.875% and for LIBOR borrowings ranges from 1.000% to 1.875%, and is determined based on our consolidated leverage ratio. In addition, we must pay credit facility fees. The credit facility contains certain restrictive covenants including maintaining a minimum fixed charge ratio of 2.5 and a maximum consolidated leverage ratio of 3.0, subject to a step up to 3.5 following certain permitted acquisitions. The credit agreement also contains other covenants typical of unsecured facilities. As of December 31, 2017, we had $420.0 million in borrowings outstanding at a weighted average interest rate of 2.655%, of which $350.0 million was classified as a long-term liability and recorded in long-term debt within the accompanying condensed consolidated balance sheets. We were in compliance with all financial covenants under this credit facility as of December 31, 2017.

Revolving Line of Credit

On November 17, 2017, we amended our credit agreement with a syndicate of banks, increasing our borrowing capacity under the unsecured revolving line of credit to $600 million. The revolving line of credit expires on December 30, 2019. Proceeds from the credit facility can be used for working capital and general corporate purposes and may also be used for the refinancing of existing debt, acquisitions and the repurchase of our common stock. Interest on amounts borrowed under the credit facility is based on (i) a base rate, which is the greater of (a) the prime rate, (b) the Federal Funds rate plus 0.500% and (c) the one-month LIBOR rate plus 1.000%, plus, in each case, an applicable margin, or (ii) an adjusted LIBOR rate plus an applicable margin. The applicable margin for base rate borrowings ranges from 0% to 0.875% and for LIBOR borrowings ranges from 1.000% to 1.875%, and is determined based on our consolidated leverage ratio. In addition, we must pay credit facility fees. The credit facility contains certain restrictive covenants including maintaining a minimum fixed charge ratio of 2.5 and a maximum consolidated leverage ratio of 3.0, subject to a step up to 3.5 following certain permitted acquisitions. The credit agreement also contains other covenants typical of unsecured facilities. As of December 31, 2017, we had $420.0 million in borrowings outstanding at a weighted average interest rate of 2.655%, of which $350.0 million was classified as a long-term liability and recorded in long-term debt within the accompanying condensed consolidated balance sheets. We were in compliance with all financial covenants under this credit facility as of December 31, 2017.