Derivative Instruments and Hedging Activities	9 Months Ended
Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities As of September 30, 2018, the Company had entered into interest rate swap contracts with an aggregate notional amount of $175.0 million that effectively fixed the interest rate on the $175.0 million unsecured term loan at 2.3%. These derivatives qualify for hedge accounting. As of September 30, 2018, the Company had interest rate caps, which are not accounted for as hedges, totaling a notional amount of $9.9 million that effectively limit the Company’s exposure to interest rate risk by providing a ceiling on the underlying variable interest rate for $9.9 million of the Company’s tax exempt variable rate debt. As of September 30, 2018 and December 31, 2017, the aggregate carrying value of the interest rate swap contracts was an asset of $8.8 million and $5.4 million, respectively, and is included in prepaid expenses and other assets on the condensed consolidated balance sheets. The aggregate carrying value of the interest rate caps was zero on the condensed consolidated balance sheets as of both September 30, 2018 and December 31, 2017. Hedge ineffectiveness related to cash flow hedges, which is included in interest expense on the condensed consolidated statements of income and comprehensive income, was not significant for the three and nine months ended September 30, 2018 and 2017. Additionally, the Company has entered into total return swaps that effectively convert $256.2 million of mortgage notes payable to a floating interest rate based on the Securities Industry and Financial Markets Association Municipal Swap Index (“SIFMA”) plus a spread. The total return swaps provide fair market value protection on the mortgage notes payable to the counterparties during the initial period of the total return swap until the Company's option to call the mortgage notes at par can be exercised. The Company can currently call all total return swaps, with $256.2 million of the outstanding debt at par. These derivatives do not qualify for hedge accounting and had a carrying and fair value of zero at both September 30, 2018 and December 31, 2017. These total return swaps are scheduled to mature between September 2021 and November 2022. The realized gains of $2.2 million and $2.5 million for the three months ended September 30, 2018 and 2017, respectively, and $6.7 million and $7.7 million for the nine months ended September 30, 2018 and 2017, respectively, were reported in the condensed consolidated statements of income and comprehensive income as total return swap income.

Derivative Instruments and Hedging Activities

As of September 30, 2018, the Company had entered into interest rate swap contracts with an aggregate notional amount of $175.0 million that effectively fixed the interest rate on the $175.0 million unsecured term loan at 2.3%. These derivatives qualify for hedge accounting.

As of September 30, 2018, the Company had interest rate caps, which are not accounted for as hedges, totaling a notional amount of $9.9 million that effectively limit the Company’s exposure to interest rate risk by providing a ceiling on the underlying variable interest rate for $9.9 million of the Company’s tax exempt variable rate debt.

As of September 30, 2018 and December 31, 2017, the aggregate carrying value of the interest rate swap contracts was an asset of $8.8 million and $5.4 million, respectively, and is included in prepaid expenses and other assets on the condensed consolidated balance sheets. The aggregate carrying value of the interest rate caps was zero on the condensed consolidated balance sheets as of both September 30, 2018 and December 31, 2017.

Hedge ineffectiveness related to cash flow hedges, which is included in interest expense on the condensed consolidated statements of income and comprehensive income, was not significant for the three and nine months ended September 30, 2018 and 2017.

Additionally, the Company has entered into total return swaps that effectively convert $256.2 million of mortgage notes payable to a floating interest rate based on the Securities Industry and Financial Markets Association Municipal Swap Index (“SIFMA”) plus a spread. The total return swaps provide fair market value protection on the mortgage notes payable to the counterparties during the initial period of the total return swap until the Company's option to call the mortgage notes at par can be exercised. The Company can currently call all total return swaps, with $256.2 million of the outstanding debt at par. These derivatives do not qualify for hedge accounting and had a carrying and fair value of zero at both September 30, 2018 and December 31, 2017. These total return swaps are scheduled to mature between September 2021 and November 2022. The realized gains of $2.2 million and $2.5 million for the three months ended September 30, 2018 and 2017, respectively, and $6.7 million and $7.7 million for the nine months ended September 30, 2018 and 2017, respectively, were reported in the condensed consolidated statements of income and comprehensive income as total return swap income.