Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01		$ 0.01
Common Stock Value Authorized Under Stock Offering Program	$ 400,000
Stock Issued During Period, Shares, New Issues	8,000,000.0	990,400
Proceeds from issuance of common shares, net	$ 272,761	$ 34,913	$ 13,383
At-the-market equity issuance [Member]
Proceeds from issuance of common shares, net	263,300	28,400
Gross Proceeds [Member] | At-the-market equity issuance [Member]
Proceeds from issuance of common shares, net	$ 266,300	$ 29,000