Basis of Presentation - Schedule of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Basic earnings per share calculation:
Net income	$ 11,239	$ 15,775	$ 20,992	$ 30,374
Weighted-average basic shares outstanding	25,741,968	17,180,000	24,944,633	17,180,000
Basic earnings per share	$ 0.44	$ 0.92	$ 0.84	$ 1.77
Diluted earnings per share:
Net income	$ 11,239	$ 15,775	$ 20,992	$ 30,374
Weighted-average basic shares outstanding	25,741,968	17,180,000	24,944,633	17,180,000
Average diluted common shares outstanding	559,490	0	505,786	0
Weighted-average diluted shares outstanding	26,301,458	17,180,000	25,450,419	17,180,000
Diluted earnings per share	$ 0.43	$ 0.92	$ 0.82	$ 1.77
Pro forma earnings per share:
Pro forma net income	$ 11,239	$ 10,576	$ 20,992	$ 20,379
Weighted-average basic shares outstanding	25,741,968	17,180,000	24,944,633	17,180,000
Pro forma basic earnings per share	$ 0.44	$ 0.62	$ 0.84	$ 1.19
Pro forma diluted earnings per share:
Pro forma net income	$ 11,239	$ 10,576	$ 20,992	$ 20,379
Weighted-average diluted shares outstanding	26,301,458	17,180,000	25,450,419	17,180,000
Pro forma diluted earnings per share	$ 0.43	$ 0.62	$ 0.82	$ 1.19