Indebtedness	6 Months Ended
Jun. 30, 2014
Indebtedness
Indebtedness	Note 5. Indebtedness Our principal debt obligations at June 30, 2014 were: (1) six public issuances of unsecured senior notes, including: (a) $250,000 principal amount at an annual interest rate of 4.30% due 2016, (b) $400,000 principal amount at an annual interest rate of 3.25% due 2019, (c) $200,000 principal amount at an annual interest rate of 6.75% due 2020, (d) $300,000 principal amount at an annual interest rate of 6.75% due 2021, (e) $250,000 principal amount at an annual interest rate of 4.75% due 2024 and (f) $350,000 principal amount at an annual interest rate of 5.625% due 2042; (2) our $350,000 principal amount term loan; and (3) $655,324 aggregate principal amount of mortgages secured by 47 of our properties (50 buildings) with maturity dates from 2015 to 2043. The 47 mortgaged properties (50 buildings) had a carrying value of $886,458 at June 30, 2014. We also had two properties subject to capital leases totaling $13,047 at June 30, 2014; these two properties had a carrying value of $18,403 at June 30, 2014. We have a $750,000 unsecured revolving credit facility that is available for general business purposes, including acquisitions. The maturity date of our revolving credit facility is January 15, 2018 and, subject to the payment of an extension fee and meeting certain other conditions, we have an option to further extend the stated maturity date by an additional one year to January 15, 2019. The revolving credit facility agreement provides that we can borrow, repay and reborrow funds available under the revolving credit facility agreement until maturity, and no principal repayment is due until maturity. The revolving credit facility agreement includes a feature under which maximum borrowings under the facility may be increased to up to $1,500,000 in certain circumstances. The interest rate paid on borrowings under the revolving credit facility agreement is LIBOR plus a premium of 130 basis points, and the facility fee is 30 basis points per annum on the total amount of lending commitments. Both the interest rate premium and the facility fee are subject to adjustment based upon changes to our credit ratings. As of June 30, 2014, the interest rate payable on borrowings under our revolving credit facility was 1.42% and the weighted average interest rate for borrowings under our revolving credit facility was 1.42% for both the three and six months ended June 30, 2014. The weighted average interest rate for borrowings under our revolving credit facility was 2.56% and 1.86% for the three and six months ended June 30, 2013, respectively. We incurred interest expense and other associated costs related to our revolving credit facility of $969 and $1,880 for the three and six months ended June 30, 2014, respectively. As of both June 30, 2014 and August 4, 2014, we had no amounts outstanding and $750,000 available for borrowing by us. Our revolving credit facility agreement provides for acceleration of payment of all amounts outstanding upon the occurrence and continuation of certain events of default, such as a change of control of us, which includes Reit Management & Research LLC, or RMR, ceasing to act as our business manager and property manager. In April 2014, we sold $400,000 of 3.25% senior unsecured notes due 2019 and $250,000 of 4.75% senior unsecured notes due 2024, raising net proceeds of approximately $644,889, after underwriting discounts but before expenses. Interest on the notes is payable semi-annually in arrears. We used the net proceeds of this offering for general business purposes, including funding the acquisitions described in Note 3. On May 30, 2014, we entered into a term loan agreement with Wells Fargo Bank, National Association and a syndicate of other lenders, pursuant to which we obtained a $350,000 unsecured term loan. Our term loan matures on January 15, 2020, and is prepayable without penalty at any time. In addition, our term loan includes a feature under which maximum borrowings may be increased to up to $700,000 in certain circumstances. Our term loan bears interest at a rate of LIBOR plus a premium of 140 basis points that is subject to adjustment based upon changes to our credit ratings. We used the net proceeds of our term loan to repay amounts outstanding under our revolving credit facility, to repay existing mortgage notes and for general business purposes. As of June 30, 2014, the interest rate payable for amounts outstanding under our term loan was 1.55%. The weighted average annual interest rate for amounts outstanding on our term loan was 1.55% for the period from May 30, 2014 to June 30, 2014. Our public debt indentures and related supplements and our credit facility 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. In connection with the acquisitions discussed in Note 3 above, during the three months ended June 30, 2014, we assumed $15,630 of mortgage debt, which was recorded at a fair value of $16,643. This mortgage has a contractual interest rate of 6.28% and matures in July 2022. We recorded the assumed mortgage at its fair value, which exceeded its outstanding principal balance by $1,013. We determined the fair value of the assumed mortgage using a market approach based upon Level 3 inputs (significant other unobservable inputs) in the fair value hierarchy. In June 2014, we repaid mortgage notes that encumbered two of our properties that had an aggregate principal balance of $35,300 and a weighted average interest rate of 5.8%.

Note 5. Indebtedness

Our principal debt obligations at June 30, 2014 were: (1) six public issuances of unsecured senior notes, including: (a) $250,000 principal amount at an annual interest rate of 4.30% due 2016, (b) $400,000 principal amount at an annual interest rate of 3.25% due 2019, (c) $200,000 principal amount at an annual interest rate of 6.75% due 2020, (d) $300,000 principal amount at an annual interest rate of 6.75% due 2021, (e) $250,000 principal amount at an annual interest rate of 4.75% due 2024 and (f) $350,000 principal amount at an annual interest rate of 5.625% due 2042; (2) our $350,000 principal amount term loan; and (3) $655,324 aggregate principal amount of mortgages secured by 47 of our properties (50 buildings) with maturity dates from 2015 to 2043. The 47 mortgaged properties (50 buildings) had a carrying value of $886,458 at June 30, 2014. We also had two properties subject to capital leases totaling $13,047 at June 30, 2014; these two properties had a carrying value of $18,403 at June 30, 2014.

We have a $750,000 unsecured revolving credit facility that is available for general business purposes, including acquisitions. The maturity date of our revolving credit facility is January 15, 2018 and, subject to the payment of an extension fee and meeting certain other conditions, we have an option to further extend the stated maturity date by an additional one year to January 15, 2019. The revolving credit facility agreement provides that we can borrow, repay and reborrow funds available under the revolving credit facility agreement until maturity, and no principal repayment is due until maturity. The revolving credit facility agreement includes a feature under which maximum borrowings under the facility may be increased to up to $1,500,000 in certain circumstances. The interest rate paid on borrowings under the revolving credit facility agreement is LIBOR plus a premium of 130 basis points, and the facility fee is 30 basis points per annum on the total amount of lending commitments. Both the interest rate premium and the facility fee are subject to adjustment based upon changes to our credit ratings. As of June 30, 2014, the interest rate payable on borrowings under our revolving credit facility was 1.42% and the weighted average interest rate for borrowings under our revolving credit facility was 1.42% for both the three and six months ended June 30, 2014. The weighted average interest rate for borrowings under our revolving credit facility was 2.56% and 1.86% for the three and six months ended June 30, 2013, respectively. We incurred interest expense and other associated costs related to our revolving credit facility of $969 and $1,880 for the three and six months ended June 30, 2014, respectively. As of both June 30, 2014 and August 4, 2014, we had no amounts outstanding and $750,000 available for borrowing by us.

Our revolving credit facility agreement provides for acceleration of payment of all amounts outstanding upon the occurrence and continuation of certain events of default, such as a change of control of us, which includes Reit Management & Research LLC, or RMR, ceasing to act as our business manager and property manager.

In April 2014, we sold $400,000 of 3.25% senior unsecured notes due 2019 and $250,000 of 4.75% senior unsecured notes due 2024, raising net proceeds of approximately $644,889, after underwriting discounts but before expenses. Interest on the notes is payable semi-annually in arrears. We used the net proceeds of this offering for general business purposes, including funding the acquisitions described in Note 3.

On May 30, 2014, we entered into a term loan agreement with Wells Fargo Bank, National Association and a syndicate of other lenders, pursuant to which we obtained a $350,000 unsecured term loan. Our term loan matures on January 15, 2020, and is prepayable without penalty at any time. In addition, our term loan includes a feature under which maximum borrowings may be increased to up to $700,000 in certain circumstances. Our term loan bears interest at a rate of LIBOR plus a premium of 140 basis points that is subject to adjustment based upon changes to our credit ratings. We used the net proceeds of our term loan to repay amounts outstanding under our revolving credit facility, to repay existing mortgage notes and for general business purposes. As of June 30, 2014, the interest rate payable for amounts outstanding under our term loan was 1.55%. The weighted average annual interest rate for amounts outstanding on our term loan was 1.55% for the period from May 30, 2014 to June 30, 2014.

Our public debt indentures and related supplements and our credit facility 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.

In connection with the acquisitions discussed in Note 3 above, during the three months ended June 30, 2014, we assumed $15,630 of mortgage debt, which was recorded at a fair value of $16,643. This mortgage has a contractual interest rate of 6.28% and matures in July 2022. We recorded the assumed mortgage at its fair value, which exceeded its outstanding principal balance by $1,013. We determined the fair value of the assumed mortgage using a market approach based upon Level 3 inputs (significant other unobservable inputs) in the fair value hierarchy.

In June 2014, we repaid mortgage notes that encumbered two of our properties that had an aggregate principal balance of $35,300 and a weighted average interest rate of 5.8%.