Employee Benefits and Retirement Plans - Pension Asset Allocation and Fair Value Measurement (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity	$ 4,302,437	$ 3,955,631
Equity, percentage	40.00%	38.00%
Fixed income	$ 1,351,048	$ 2,670,663
Fixed income, percentage	13.00%	25.00%
Total	$ 5,653,485	$ 6,626,294
Total, percentage	53.00%	63.00%
Certificates of deposit	$ 4,283,144	$ 3,514,182
Certificates of deposits, percentage	40.00%	33.00%
Cash and cash equivalent	$ 736,182	$ 433,669
Cash and cash equivalents, percentage	7.00%	4.00%
Total	$ 5,019,326	$ 3,947,851
Total, percentage	47.00%	37.00%
Fair value of plan assets	$ 10,672,811	$ 10,574,145	$ 11,420,270	$ 11,889,678
Fair value of plan assets, percentage	100.00%	100.00%
Level 1 [Member]
Equity	$ 4,302,437	$ 3,955,631
Fixed income	1,351,048	2,670,663
Total	5,653,485	6,626,294
Certificates of deposit	4,283,144	3,514,182
Cash and cash equivalent	736,182	433,669
Total	5,019,326	3,947,851
Fair value of plan assets	$ 10,672,811	$ 10,574,145