Stockholders' Equity - Equity Offering Programs (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Mar. 19, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 31, 2020
Class of Stock [Line Items]
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Net proceeds		$ 295,946	$ 611	$ 248,554
At The Market Equity Offering Program [Member]
Class of Stock [Line Items]
Issuance of common stock (shares)		5,470,673	0	0
Net proceeds		$ 179,100	$ 0	$ 0
Minimum [Member] | At The Market Equity Offering Program [Member]
Class of Stock [Line Items]
Shares issued during period (in dollars per share)		$ 32.01
Maximum [Member] | At The Market Equity Offering Program [Member]
Class of Stock [Line Items]
Shares issued during period (in dollars per share)		$ 33.77
Subsequent Event [Member] | At The Market Equity Offering Program [Member]
Class of Stock [Line Items]
Number of authorized shares remaining under offering program (shares)					398,024
Equity Offering [Member]
Class of Stock [Line Items]
Issuance of common stock (shares)	3,737,500
Common stock, par value (in dollars per share)	$ 0.01
Net proceeds	$ 115,800
Shares issued in equity offering (in dollars per share)	$ 31.40