Equity	3 Months Ended
Mar. 31, 2018
Equity [Abstract]
Equity	Equity Stockholders’ Equity On February 26, 2018, the Company commenced an at-the-market continuous equity offering program (the “ATM Program”) through which the Company may, from time to time, issue and sell shares of its common stock having an aggregate offering price of up to $125.0 million. During the three months ended March 31, 2018, the Company did not issue any shares of common stock under the ATM Program. As of March 31, 2018 and December 31, 2017, the Company’s authorized capital was 500 million shares of common stock and 100 million shares of preferred stock. The Company had 45,205,575 and 44,937,763 shares of common stock issued and outstanding as of March 31, 2018 and December 31, 2017, respectively. No shares of preferred stock were issued and outstanding as of March 31, 2018 or December 31, 2017. Noncontrolling Interests As of March 31, 2018 and December 31, 2017, the Company held a 72.2% and 72.0% interest, respectively, in the Operating Partnership. The Company is the primary beneficiary of the Operating Partnership as it has the power to direct the activities of the Operating Partnership and the rights to absorb 72.2% of the net income of the Operating Partnership. As the primary beneficiary, the Company consolidates the financial position and results of operations of the Operating Partnership. Noncontrolling interests in the Company represent units of limited partnership interest in the Operating Partnership not held by the Company. As of March 31, 2018, there were 17,440,861 Class A Units not held by the Company. The Company's financial position and results of operations are the same as those of the Operating Partnership. The noncontrolling interest for the consolidated entities under development or construction (see Note 1) was zero as of March 31, 2018 and December 31, 2017. On January 2, 2018, due to the holders of Class A Units tendering an aggregate of 163,000 Class A Units for redemption by the Operating Partnership, the Company elected to satisfy the redemption request through the issuance of an equal number of shares of common stock. As partial consideration for the acquisition of Columbus Village, the Operating Partnership issued 1,000,000 class B units of limited partnership interest in the Operating Partnership ("Class B Units") on July 10, 2015 and issued 275,000 class C units of limited partnership interest in the Operating Partnership ("Class C Units") on January 10, 2017. The Class B Units were automatically converted to Class A Units on July 10, 2017. The Class C Units were automatically converted into Class A Units on January 10, 2018. As partial consideration for the acquisition of Parkway Centre, the Operating Partnership issued 117,228 Class A Units on January 29, 2018. Common Stock Dividends and Class A Unit Distributions On January 4, 2018, the Company paid cash dividends of $8.5 million to common stockholders and the Operating Partnership paid cash distributions of $3.3 million to holders of Class A Units. On February 22, 2018, the Board of Directors declared a cash dividend and distribution of $0.20 per share and unit payable on April 5, 2018 to stockholders and unitholders of record on March 28, 2018. Subsequent to March 31, 2018 On April 2, 2018, due to the holders of Class A Units tendering an aggregate of 187,142 Class A Units for redemption by the Operating Partnership, the Company elected to satisfy the redemption request with an aggregate cash payment of $2.5 million. On April 5, 2018, the Company paid cash dividends of $9.0 million to common stockholders and the Operating Partnership paid cash distributions of $3.5 million to holders of Class A Units. On April 17, 2018, the Operating Partnership issued 36,684 Class A Units to the former noncontrolling interest holder of John Hopkins Village due to the satisfaction of a contingent event that was part of the redemption of its redeemable noncontrolling interest in Johns Hopkins Village in December 2017. During April 2018, the Company issued and sold an aggregate of 31,468 shares of common stock at a weighted average price of $13.79 per share under the ATM Program, receiving net proceeds, after offering costs and commissions, of $0.4 million.

Equity

Stockholders’ Equity

On February 26, 2018, the Company commenced an at-the-market continuous equity offering program (the “ATM Program”) through which the Company may, from time to time, issue and sell shares of its common stock having an aggregate offering price of up to $125.0 million. During the three months ended March 31, 2018, the Company did not issue any shares of common stock under the ATM Program.

As of March 31, 2018 and December 31, 2017, the Company’s authorized capital was 500 million shares of common stock and 100 million shares of preferred stock. The Company had 45,205,575 and 44,937,763 shares of common stock issued and outstanding as of March 31, 2018 and December 31, 2017, respectively. No shares of preferred stock were issued and outstanding as of March 31, 2018 or December 31, 2017.

Noncontrolling Interests

As of March 31, 2018 and December 31, 2017, the Company held a 72.2% and 72.0% interest, respectively, in the Operating Partnership. The Company is the primary beneficiary of the Operating Partnership as it has the power to direct the activities of the Operating Partnership and the rights to absorb 72.2% of the net income of the Operating Partnership. As the primary beneficiary, the Company consolidates the financial position and results of operations of the Operating Partnership. Noncontrolling interests in the Company represent units of limited partnership interest in the Operating Partnership not held by the Company. As of March 31, 2018, there were 17,440,861 Class A Units not held by the Company. The Company's financial position and results of operations are the same as those of the Operating Partnership. The noncontrolling interest for the consolidated entities under development or construction (see Note 1) was zero as of March 31, 2018 and December 31, 2017.

On January 2, 2018, due to the holders of Class A Units tendering an aggregate of 163,000 Class A Units for redemption by the Operating Partnership, the Company elected to satisfy the redemption request through the issuance of an equal number of shares of common stock.

As partial consideration for the acquisition of Columbus Village, the Operating Partnership issued 1,000,000 class B units of limited partnership interest in the Operating Partnership ("Class B Units") on July 10, 2015 and issued 275,000 class C units of limited partnership interest in the Operating Partnership ("Class C Units") on January 10, 2017. The Class B Units were automatically converted to Class A Units on July 10, 2017. The Class C Units were automatically converted into Class A Units on January 10, 2018.

As partial consideration for the acquisition of Parkway Centre, the Operating Partnership issued 117,228 Class A Units on January 29, 2018.

Common Stock Dividends and Class A Unit Distributions

On January 4, 2018, the Company paid cash dividends of $8.5 million to common stockholders and the Operating Partnership paid cash distributions of $3.3 million to holders of Class A Units.

On February 22, 2018, the Board of Directors declared a cash dividend and distribution of $0.20 per share and unit payable on April 5, 2018 to stockholders and unitholders of record on March 28, 2018.

Subsequent to March 31, 2018

On April 2, 2018, due to the holders of Class A Units tendering an aggregate of 187,142 Class A Units for redemption by the Operating Partnership, the Company elected to satisfy the redemption request with an aggregate cash payment of $2.5 million.

On April 5, 2018, the Company paid cash dividends of $9.0 million to common stockholders and the Operating Partnership paid cash distributions of $3.5 million to holders of Class A Units.

On April 17, 2018, the Operating Partnership issued 36,684 Class A Units to the former noncontrolling interest holder of John Hopkins Village due to the satisfaction of a contingent event that was part of the redemption of its redeemable noncontrolling interest in Johns Hopkins Village in December 2017.

During April 2018, the Company issued and sold an aggregate of 31,468 shares of common stock at a weighted average price of $13.79 per share under the ATM Program, receiving net proceeds, after offering costs and commissions, of $0.4 million.