Shareholders' Equity (Details) $ / shares in Units, $ in Thousands					1 Months Ended	12 Months Ended
	Dec. 14, 2020 USD ($) $ / shares shares	Dec. 12, 2019 USD ($)	Dec. 10, 2019 USD ($) $ / shares shares	Apr. 18, 2019 USD ($) $ / shares shares	Jan. 31, 2019 USD ($) shares	Dec. 31, 2020 USD ($) Vote $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) shares
Common Stock [Abstract]
Common stock, shares authorized (in shares) | shares						120,000,000	120,000,000
Common stock, par value (in dollars per share) | $ / shares						$ 0.01	$ 0.01
Number of voting right for each share | Vote						1
Treasury Stock [Abstract]
Retirement of treasury stock (in shares) | shares					100,000
Retirement of treasury stock					$ 1,300		$ 0
Shares withheld to pay the payroll tax liability						$ 614	344	$ 0
Public Offering [Abstract]
Net proceeds from offering						$ 280,763	$ 177,760	$ 154,022
Common Stock [Member]
Treasury Stock [Abstract]
Retirement of treasury stock (in shares) | shares							100,000
Retirement of treasury stock							$ 1
Public Offering [Abstract]
Common stock shares issued (in shares) | shares						5,339,286	9,568,000	11,475,242
Common Stock [Member] | Public Offering [Member]
Public Offering [Abstract]
Common stock shares issued (in shares) | shares	5,339,286		4,393,000	5,175,000		5,339,286
Share price (in dollars per share) | $ / shares	$ 56.00		$ 22.25	$ 17.50
Gross proceeds, offering amount	$ 299,000		$ 99,700	$ 90,600
Offering costs	18,200		6,100	4,500
Net proceeds from offering	$ 280,800		$ 91,700	$ 86,100
Common Stock [Member] | Exercise of Underwriters' Option [Member]
Public Offering [Abstract]
Common stock shares issued (in shares) | shares	696,428		573,000	675,000
Treasury Stock [Member]
Treasury Stock [Abstract]
Retirement of treasury stock							$ (1,393)
Shares withheld to pay the payroll tax liability		$ 100
Additional Paid-In Capital [Member]
Treasury Stock [Abstract]
Retirement of treasury stock							$ 1,392