Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic and Diluted Earnings Per Share
Net income available to common stockholders, basic and diluted	$ 49,132	$ 38,559
Average outstanding shares - basic	84,549,974	80,808,904
Add: dilutive restricted stock awards and stock options	64,274	78,231
Average outstanding shares - diluted	84,614,248	80,887,135
Basic earnings per share	$ 0.58	$ 0.48
Diluted earnings per share	$ 0.58	$ 0.48
Earnings Per Share
Restricted stock awards and stock options excluded from the diluted average outstanding share calculation	41,593	0