Income Taxes (Details 1)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summary of effective income tax rate differed from the statutory U.S. federal income tax rate
Federal income tax rate	21.00%	35.00%
State income taxes, net of federal benefit	5.10%	3.80%
Permanent differences	(1.20%)	(20.50%)
Non-controlling interest in consolidated partnerships	(9.80%)	(0.80%)
True-up of prior year depletion in excess of basis	1.30%	1.10%
Stock-based compensation deficiency	1.10%	3.10%
Rate changes of prior year deferred	(1.00%)	(1.80%)
True-up of prior year deferred	4.00%	(4.50%)
Effect of tax cuts and TCJA		91.00%
Increase in valuation allowance and other	2.00%	(107.70%)
Total effective income tax rate	22.50%	(1.10%)