Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 57,914	$ 18,619	$ 77,049	$ 33,846
Weighted Average Common Shares, Basic EPS	45,548,000	45,387,000	45,500,000	45,363,000
Weighted Average Common Shares, Dilutive effect of nonvested share awards	439,000	108,000	386,000	94,000
Weighted Average Common Shares, Diluted EPS	45,987,000	45,495,000	45,886,000	45,457,000
EPS, Basic (in dollars per share)	$ 1.27	$ 0.41	$ 1.69	$ 0.75
EPS, Dilutive effect of nonvested share awards (in dollars per share)	(0.01)	0	(0.01)	(0.01)
EPS, Diluted (in dollars per share)	$ 1.26	$ 0.41	$ 1.68	$ 0.74
Antidilutive options outstanding	0	0	0	0