Indebtedness	9 Months Ended
Sep. 30, 2014
Debt Disclosure [Abstract]
Indebtedness	Indebtedness Unsecured Revolving Credit Facility and Unsecured Term Loan: We have a $750.0 million unsecured revolving credit facility, with availability of $747.5 million, that matures on October 19, 2015, that is used for general business purposes, including acquisitions. We also have a $500.0 million unsecured term loan that matures on December 15, 2016. Borrowings under our revolving credit facility bear interest at LIBOR plus a premium, which was 150 basis points as of September 30, 2014. We also pay a facility fee of 35 basis points per annum on the total amount of lending commitments under our revolving credit facility. Both the interest rate premium and the facility fee are subject to adjustment based upon changes to our credit ratings. As of September 30, 2014, the interest rate payable on borrowings under our revolving credit facility was 1.7%. The weighted average interest rate for borrowings under our revolving credit facility was 1.7% for both the nine months ended September 30, 2014 and 2013, respectively. On July 18, 2014, we paid off the entire balance of $235.0 million on our revolving credit facility, and no balance remained outstanding as of September 30, 2014. Our term loan bears interest at a rate of LIBOR plus a premium, which was 185 basis points as of September 30, 2014. The interest rate premium is subject to adjustment based upon changes to our credit ratings. As of September 30, 2014, the interest rate for the amount outstanding under our term loan was 2.0%. The weighted average interest rate for the amount outstanding under our term loan was 2.0% and 2.1% for the nine months ended September 30, 2014 and 2013, respectively. Credit Facility and Term Loan Debt Covenants: Our public debt indenture and related supplements, our revolving credit facility agreement and our term loan agreement contain a number of financial and other covenants, including covenants that restrict our ability to incur indebtedness or to make distributions under certain circumstances and require us to maintain financial ratios and a minimum net worth. At September 30, 2014, we believe we were in compliance with all of our respective covenants under our public debt indenture and related supplements, our revolving credit facility and our term loan agreements. Senior Unsecured Debt: On September 15, 2014, we prepaid at par $33.4 million of our 6.40% unsecured senior notes due 2015. Mortgage Notes Payable: At September 30, 2014, 11 of our properties (15 buildings) with an aggregate net book value of $724.4 million, had secured mortgage notes totaling $619.8 million (including net premiums and discounts) maturing from 2015 through 2026. On August 1, 2014, we prepaid at par the $265.0 million of 5.68% mortgage debt at 600 West Chicago Avenue and recognized a net gain on early extinguishment of debt of $6.7 million from the write-off of an unamortized premium and deferred financing fees. On June 27, 2014, we repaid $11.2 million of 6.14% mortgage debt and $8.5 million of 5.78% mortgage debt in connection with the sale of the related properties and recognized a loss on early extinguishment of debt of $3.3 million from prepayment premiums and the write-off of unamortized discounts and deferred financing fees. During the quarter ended June 30, 2014, we made the decision to cease making loan servicing payments on One Enterprise Center in Jacksonville, Florida. The first payment we determined not to make for this property was due on June 11, 2014. The property is secured by a non-recourse mortgage loan, with a current principal balance of $40.1 million. On October 10, 2014, we were notified by the lender that our decision to cease making loan servicing payments created an event of default effective July 11, 2014 and the lender has exercised its option to accelerate the maturity of the unpaid balance of the loan. On March 11, 2014, we prepaid at par the $12.0 million of 4.95% mortgage debt at 3920 Arkwright Road using cash on hand.

Indebtedness

Unsecured Revolving Credit Facility and Unsecured Term Loan:

We have a $750.0 million unsecured revolving credit facility, with availability of $747.5 million, that matures on October 19, 2015, that is used for general business purposes, including acquisitions. We also have a $500.0 million unsecured term loan that matures on December 15, 2016. Borrowings under our revolving credit facility bear interest at LIBOR plus a premium, which was 150 basis points as of September 30, 2014. We also pay a facility fee of 35 basis points per annum on the total amount of lending commitments under our revolving credit facility. Both the interest rate premium and the facility fee are subject to adjustment based upon changes to our credit ratings. As of September 30, 2014, the interest rate payable on borrowings under our revolving credit facility was 1.7%. The weighted average interest rate for borrowings under our revolving credit facility was 1.7% for both the nine months ended September 30, 2014 and 2013, respectively. On July 18, 2014, we paid off the entire balance of $235.0 million on our revolving credit facility, and no balance remained outstanding as of September 30, 2014.

Our term loan bears interest at a rate of LIBOR plus a premium, which was 185 basis points as of September 30, 2014. The interest rate premium is subject to adjustment based upon changes to our credit ratings. As of September 30, 2014, the interest rate for the amount outstanding under our term loan was 2.0%. The weighted average interest rate for the amount outstanding under our term loan was 2.0% and 2.1% for the nine months ended September 30, 2014 and 2013, respectively.

Credit Facility and Term Loan Debt Covenants:

Our public debt indenture and related supplements, our revolving credit facility agreement and our term loan agreement contain a number of financial and other covenants, including covenants that restrict our ability to incur indebtedness or to make distributions under certain circumstances and require us to maintain financial ratios and a minimum net worth. At September 30, 2014, we believe we were in compliance with all of our respective covenants under our public debt indenture and related supplements, our revolving credit facility and our term loan agreements.

Senior Unsecured Debt:

On September 15, 2014, we prepaid at par $33.4 million of our 6.40% unsecured senior notes due 2015.

Mortgage Notes Payable:

At September 30, 2014, 11 of our properties (15 buildings) with an aggregate net book value of $724.4 million, had secured mortgage notes totaling $619.8 million (including net premiums and discounts) maturing from 2015 through 2026.

On August 1, 2014, we prepaid at par the $265.0 million of 5.68% mortgage debt at 600 West Chicago Avenue and recognized a net gain on early extinguishment of debt of $6.7 million from the write-off of an unamortized premium and deferred financing fees.

On June 27, 2014, we repaid $11.2 million of 6.14% mortgage debt and $8.5 million of 5.78% mortgage debt in connection with the sale of the related properties and recognized a loss on early extinguishment of debt of $3.3 million from prepayment premiums and the write-off of unamortized discounts and deferred financing fees.

During the quarter ended June 30, 2014, we made the decision to cease making loan servicing payments on One Enterprise Center in Jacksonville, Florida. The first payment we determined not to make for this property was due on June 11, 2014. The property is secured by a non-recourse mortgage loan, with a current principal balance of $40.1 million. On October 10, 2014, we were notified by the lender that our decision to cease making loan servicing payments created an event of default effective July 11, 2014 and the lender has exercised its option to accelerate the maturity of the unpaid balance of the loan.

On March 11, 2014, we prepaid at par the $12.0 million of 4.95% mortgage debt at 3920 Arkwright Road using cash on hand.