Common Stock	3 Months Ended
Mar. 31, 2020
Stockholders' Equity Note [Abstract]
Common Stock	Note 6 – Common Stock Follow-on Public Offerings In September 2018, the Company entered into a follow-on public offering of 3,500,000 shares of common stock in connection with a forward sale agreement (the “September 2018 Forward”). The September 2018 Forward was settled in its entirety in April 2019. Upon settlement we issued 3,500,000 shares of common stock and received net proceeds of $186.0 million, after deducting fees and expenses. In April 2019, the Company entered into a follow-on public offering (the “April 2019 Forward”) to sell an aggregate of 3,162,500 shares of common stock, which included the full exercise of the underwriters’ option to purchase an additional 412,500 shares of common stock. The April 2019 Forward was settled in its entirety in December 2019. Upon settlement, the Company issued 3,162,500 shares of common stock and received net proceeds of approximately $195.8 million, after deducting fees and expenses. Refer to Note 13 – Subsequent Events regarding the Company’s April 2020 common stock issuance. ATM Programs 2019 ATM Program In July 2019, the Company entered into a $400.0 million at-the-market equity (“ATM”) program (the “2019 ATM Program”) through which the Company, from time to time, sold shares of common stock. In addition to selling shares of common stock, the Company entered into forward sale agreements through the 2019 ATM Program. During the third quarter of 2019, the Company issued 444,228 shares under the 2019 ATM Program, at an average price of $74.30, realizing gross proceeds of $33.0 million. During the fourth quarter of 2019, the Company entered into forward sale agreements in connection with the 2019 ATM Program to sell an aggregate of 2,003,118 shares of common stock (the “2019 ATM Forward Offerings”). During the three months ended March 31, 2020, the Company settled 1,245,118 shares from the 2019 ATM Forward Offerings. The Company is required to settle the remaining 758,000 shares under the 2019 ATM Forward Offerings by December 2020. During the first quarter of 2020, the Company entered into forward sale agreements in connection with the 2019 ATM Program to sell an aggregate of 3,169,754 shares of common stock (the “2020 ATM Forward Offerings”). During the three months ended March 31, 2020 the Company settled 155,133 shares from the 2020 ATM Forward Offerings. The Company is required to settle the remaining 3,014,621 shares under the 2020 ATM Forward Offerings by certain dates between January 2021 and March 2021. The 2019 ATM Program was terminated simultaneously with the establishment of the 2020 ATM Program, which is discussed below. As a result, no future issuances will occur under the 2019 ATM Program. 2020 ATM Program In March 2020, the Company entered into a new $400.0 million ATM program (the “2020 ATM Program”) through which the Company, from time to time, may sell shares of common stock. In addition to selling shares of common stock, the Company may enter into forward sale agreements through the 2020 ATM Program. During the first quarter of 2020, the Company entered into a forward sale agreement in connection with the 2020 ATM Program to sell an aggregate of 204,074 shares of common stock. As of March 31, 2020, no shares have been settled under the 2020 ATM Program. The Company is required to settle the 204,074 outstanding shares under the 2020 ATM Program by April 2021. After considering the 204,074 shares of common stock subject to the forward sale agreement, the Company had approximately $387.3 million of availability remaining under the 2020 ATM Program as of March 31, 2020. 2018 ATM Program In May 2018, the Company entered into a $250.0 million at-the-market equity program (“2018 ATM Program”) through which the Company, from time to time, sold shares of common stock. In addition to selling shares of common stock, the Company entered into forward sale agreements through the 2018 ATM Program. During the three months ended March 31, 2019, the Company did not issue shares of common stock under the 2018 ATM Program. The 2018 ATM Program was terminated, and no future issuances will occur under the 2018 ATM Program.

Common Stock

3 Months Ended

Mar. 31, 2020

Stockholders' Equity Note [Abstract]

Note 6 – Common Stock

Follow-on Public Offerings

In September 2018, the Company entered into a follow-on public offering of 3,500,000 shares of common stock in connection with a forward sale agreement (the “September 2018 Forward”). The September 2018 Forward was settled in its entirety in April 2019. Upon settlement we issued 3,500,000 shares of common stock and received net proceeds of $186.0 million, after deducting fees and expenses.

In April 2019, the Company entered into a follow-on public offering (the “April 2019 Forward”) to sell an aggregate of 3,162,500 shares of common stock, which included the full exercise of the underwriters’ option to purchase an additional 412,500 shares of common stock. The April 2019 Forward was settled in its entirety in December 2019. Upon settlement, the Company issued 3,162,500 shares of common stock and received net proceeds of approximately $195.8 million, after deducting fees and expenses.

Refer to Note 13 – Subsequent Events regarding the Company’s April 2020 common stock issuance.

ATM Programs

2019 ATM Program

In July 2019, the Company entered into a $400.0 million at-the-market equity (“ATM”) program (the “2019 ATM Program”) through which the Company, from time to time, sold shares of common stock. In addition to selling shares of common stock, the Company entered into forward sale agreements through the 2019 ATM Program. During the third quarter of 2019, the Company issued 444,228 shares under the 2019 ATM Program, at an average price of $74.30, realizing gross proceeds of $33.0 million.

During the fourth quarter of 2019, the Company entered into forward sale agreements in connection with the 2019 ATM Program to sell an aggregate of 2,003,118 shares of common stock (the “2019 ATM Forward Offerings”). During the three months ended March 31, 2020, the Company settled 1,245,118 shares from the 2019 ATM Forward Offerings. The Company is required to settle the remaining 758,000 shares under the 2019 ATM Forward Offerings by December 2020.

During the first quarter of 2020, the Company entered into forward sale agreements in connection with the 2019 ATM Program to sell an aggregate of 3,169,754 shares of common stock (the “2020 ATM Forward Offerings”). During the three months ended March 31, 2020 the Company settled 155,133 shares from the 2020 ATM Forward Offerings. The Company is required to settle the remaining 3,014,621 shares under the 2020 ATM Forward Offerings by certain dates between January 2021 and March 2021.

The 2019 ATM Program was terminated simultaneously with the establishment of the 2020 ATM Program, which is discussed below. As a result, no future issuances will occur under the 2019 ATM Program.

2020 ATM Program

In March 2020, the Company entered into a new $400.0 million ATM program (the “2020 ATM Program”) through which the Company, from time to time, may sell shares of common stock. In addition to selling shares of common stock, the Company may enter into forward sale agreements through the 2020 ATM Program.

During the first quarter of 2020, the Company entered into a forward sale agreement in connection with the 2020 ATM Program to sell an aggregate of 204,074 shares of common stock. As of March 31, 2020, no shares have been settled under the 2020 ATM Program. The Company is required to settle the 204,074 outstanding shares under the 2020 ATM Program by April 2021.

After considering the 204,074 shares of common stock subject to the forward sale agreement, the Company had approximately $387.3 million of availability remaining under the 2020 ATM Program as of March 31, 2020.

2018 ATM Program

In May 2018, the Company entered into a $250.0 million at-the-market equity program (“2018 ATM Program”) through which the Company, from time to time, sold shares of common stock. In addition to selling shares of common stock, the Company entered into forward sale agreements through the 2018 ATM Program. During the three months ended March 31, 2019, the Company did not issue shares of common stock under the 2018 ATM Program. The 2018 ATM Program was terminated, and no future issuances will occur under the 2018 ATM Program.