Earnings Per Share - Calculations of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net Income	$ 78,912	$ 86,868	$ 102,265	$ 57,158
Less: Unrealized gain on financial instruments, net of tax	0	(43,379)	0	0
Diluted Net income	$ 78,912	$ 43,489	$ 102,265	$ 57,158
Denominator:
Basic EPS weighted average shares outstanding	26,129	25,851	26,048	25,794
Effect of dilutive warrants	9	1,089	4	0
Effect of dilutive restricted stock	44	13	22	127
Diluted EPS weighted average shares outstanding	26,182	26,953	26,074	25,921
Earnings per share:
Basic	$ 3.02	$ 3.36	$ 3.93	$ 2.22
Diluted	$ 3.01	$ 1.61	$ 3.92	$ 2.21