Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income		$ 47,014	$ 29,600	$ 93,072	$ 63,110
Net income applicable to non-vested restricted shares		(389)	(240)	(792)	(551)
Net income applicable to common shares		$ 46,625	$ 29,360	$ 92,280	$ 62,559
Weighted-average common shares outstanding:
Weighted-average common shares outstanding (basic) (in Shares)		108,467	102,159	107,126	102,041
Dilutive effect of common stock equivalents (in Shares)		0	0	0	8
Weighted-average diluted common shares outstanding (in Shares)		108,467	102,159	107,126	102,049
Basic EPS (in dollars per share)		$ 0.43	$ 0.29	$ 0.86	$ 0.61
Diluted EPS (in dollars per share)		$ 0.43	$ 0.29	$ 0.86	$ 0.61
Anti-dilutive shares not included in the computation of diluted EPS (in Shares)	[1]	0	0	0	54

[1] This amount represents outstanding stock options for which the exercise price is greater than the average market price of the Company's common stock. The final outstanding stock options were exercised during the first quarter of 2018.