Earnings per Share (Reconciliation between Basic and Diluted Earnings per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income for basic and diluted earnings per share	$ 25,710	$ 26,208
Basic weighted average shares outstanding	30,524	31,482
Dilutive effect of stock options and restricted stock awards	80	177
Diluted weighted average shares outstanding	30,604	31,659
Basic earnings per common share	$ 0.84	$ 0.83
Diluted earnings per common share	$ 0.84	$ 0.83