Statements of Cash Flow - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Statement of Cash Flows [Abstract]
Net income	$ 7,148,793	$ 52,462,977
Depreciation and amortization expense	6,131,118	7,098,394
Gain on sale of marketable securities	0	(1,578,402)
Loss on sale of fixed assets	0	532,297
Change in marketable securities	55,448,363	(30,321,710)
Change in trade receivables, net of reserve	(11,290,233)	1,684,241
Change in contract assets, prepaid and other	(280,528)	(1,005,513)
Change in deferred tax assets	(232,582)	(828,311)
Change in accounts payable	415,216	(326,538)
Change in taxes payable	4,661,765	468,060
Change in accrued expenses	173,149	(1,019,392)
Change in deferred revenue	6,573,560	(2,943,784)
Change in deferred tax liabilities	(13,288,864)	6,936,792
Change in tax reserves	(938,027)	(1,180,858)
Net cash from operations	54,521,730	29,978,253
Purchases of marketable securities	0	(26,585,470)
Sales of marketable securities	10,000,000	20,186,674
Purchases of fixed assets	(1,407,236)	(2,834,842)
Sales of fixed assets	0	6,711,896
Change in other assets	50,741	189,005
Net cash (used in) from investing	8,643,505	(2,332,737)
Dividends paid	(39,422,305)	(41,653,756)
Net cash used in financing	(39,422,305)	(41,653,756)
Net change in cash and equivalents	23,742,930	(14,008,240)
Cash and equivalents at beginning	14,997,613	23,095,977
Cash and equivalents at end	$ 38,740,543	$ 9,087,737