Income Per Common Share - Schedule of Basic and Diluted Income Per Common Share Calculation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Basic weighted average number of common shares outstanding (in shares)	37,818,127	38,017,211	37,715,019	37,974,471
Effect of dilutive securities:
Diluted average shares outstanding (in shares)	39,260,702	39,688,271	39,051,131	39,772,437
Net income available to common stockholders	$ 10,451	$ 22,455	$ 18,570	$ 30,783
Basic income per common share (in USD per share)	$ 0.28	$ 0.59	$ 0.49	$ 0.81
Dilutive income per common share (in USD per share)	$ 0.27	$ 0.57	$ 0.48	$ 0.77
Stock Options, Unvested Common Shares, and Warrants
Effect of dilutive securities:
Stock options, unvested common shares, and warrants (in shares)	1,442,575	1,671,060	1,336,112	1,797,966