Defined Benefit Pension Plan (401(k) Plan) (Details) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Pension Plan
Percentage of Company's 401(k) matching contribution			50.00%	50.00%
Cap on Company's matching contribution			3.00%	2.00%
Expense associated with 401(k)	$ 66,125	$ 95,000