Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Basic Earnings Per Share
Net income		$ 72,404,403	$ 86,506,418	$ 159,933,028	$ 199,957,288
Less: Dividends and undistributed earnings allocated to participating securities		1,094,827	1,324,767	2,460,845	2,974,367
Net Income available to common shareholders		$ 71,309,576	$ 85,181,651	$ 157,472,183	$ 196,982,921
Basic weighted average shares outstanding		230,982,301	238,602,197	231,245,466	238,198,668
Net income per share - Basic (in dollars per share)	[1]	$ 0.31	$ 0.36	$ 0.68	$ 0.83
Diluted Earnings Per Share
Allocation of Net Income used in basic computation		$ 71,309,576	$ 85,181,651	$ 157,472,183	$ 196,982,921
Reallocation of undistributed earnings		1,295	3,980	3,701	10,464
Net Income available to common shareholders - Diluted		$ 71,310,871	$ 85,185,631	$ 157,475,884	$ 196,993,385
Number of shares used in basic computation		230,982,301	238,602,197	231,245,466	238,198,668
Additional weighted average dilutive common stock equivalents (in shares)		456,483	1,130,301	544,919	1,218,528
Diluted weighted average shares outstanding		231,438,784	239,732,498	231,790,385	239,417,196
Net Income per share - Diluted (in dollars per share)	[1]	$ 0.31	$ 0.36	$ 0.68	$ 0.82
Shares related to stock plans not included in diluted average common shares outstanding because their effect would be anti-dilutive		1,792,677	270,475	1,549,824	137,484

[1] (1) Earnings Per Share has been adjusted to exclude the portion of net income allocated to participating securities as a result of share-based payment awards.