Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($)	3 Months Ended								9 Months Ended
	Sep. 30, 2019		Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018		Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019		Sep. 30, 2018
Numerator:
Net income	$ 50,000,000	[1]	$ 39,000,000	$ 55,000,000	$ 40,533,279	[1]	$ 107,000,000	$ 30,000,000	$ 144,352,584	[1]	$ 177,564,538	[1]
Denominator:
Weighted average shares outstanding, Basic	85,704,321				96,840,685				89,863,807		97,407,644
Basic EPS	$ 0.59				$ 0.42				$ 1.61		$ 1.82
Denominator:
Weighted average shares outstanding, diluted	86,272,979				97,432,015				90,348,418		98,142,238
Diluted EPS	$ 0.59				$ 0.42				$ 1.60		$ 1.81

[1] Net income for the three months ended September 30, 2019 and 2018 was $50,659,927 and $40,533,279, respectively, and for the nine months ended September 30, 2019