Commitments and Contingencies (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($) Lawsuit	Dec. 31, 2015 USD ($)
Estimated expenses and liabilities [Abstract]
Estimated expenses and liabilities	$ 2,243,000	$ 2,086,000
Medical Accrual [Abstract]
Accrued medical claims	1,668,000	1,107,000
Minimum annual individual medical claims for stop loss coverage	100,000
Umbrella insurance coverage	2,000,000
Minimum aggregate medical claims for umbrella insurance coverage per calendar year	$ 4,500,000	4,500,000
Number of claims alleging subsidence caused by oil and gas production | Lawsuit	1
Total number of law suits | Lawsuit	3
Future legal cost accrued	$ 500,000	$ 500,000