Earnings per Share - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 21, 2017	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		274,000	84,000
Stock Issued During Period, Shares, New Issues	2,702,500
Proceeds from Issuance of Common Stock	$ 55,700	$ 0	$ 55,660
CapGen Capital Group III LP [Member]
Stock Issued During Period, Shares, New Issues	6,210,000