Subsequent Events - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended				12 Months Ended								12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 ASD Credit Agreement [Member]	Apr. 26, 2013 ASD Credit Agreement [Member]	Dec. 31, 2013 Purchase and Sale Agreement [Member] acre Well	Dec. 31, 2013 Purchase and Sale Agreement [Member] Wetzel County [Member]	Dec. 31, 2013 Purchase and Sale Agreement [Member] Marshall County [Member]	Dec. 31, 2013 Minimum [Member] ASD Credit Agreement [Member]	Dec. 31, 2013 First Anniversary [Member]	Dec. 31, 2013 Second Anniversary To Third Anniversary [Member]	Dec. 31, 2013 Net Profits Interest Agreement [Member]	Dec. 31, 2013 Net Profits Interest Agreement [Member] Minimum [Member]	May 21, 2014 Subsequent Event [Member]	May 21, 2014 Subsequent Event [Member] Maximum [Member]	May 21, 2014 Subsequent Event [Member] Committed [Member]	May 21, 2014 Subsequent Event [Member] Uncommitted [Member]	Dec. 31, 2013 Condition [Member] Purchase and Sale Agreement [Member]
Subsequent Event [Line Items]
Credit facility, face amount		$ 50	$ 50										$ 200
Initial withdrawal amount	102.5											102.5
Remaining borrowing capacity	47.5													47.5	50.0
Debt instrument, interest rate description		Interest at a per annum rate equal to 9% plus the greater of 1% or LIBOR, for a three month interest period.
Debt instrument, additional interest rate		1.00%
Debt instrument interest rate		9.00%
Additional interest rate upon the occurrence of default		2.00%
Credit facility, maturity date	Dec. 31, 2018
Scheduled amortization beginning period	May 01, 2015
Minimum amortization requirement, description	The minimum amortization required each month will be the greater of (i) 0.75% of the then outstanding balance (after May 1, 2016) or (ii) the amortization amount that would be required for American Shale to achieve a predetermined Net Debt Ratio within six months.
Loans, prepayment charge								4.00%	3.00%
Loans, prepayment amount exempt from charges	25
Minimum percentage of capital expenditures							50.00%
Payment percentage on outstanding interest, make-wholes and fees		101.00%
Percentage of net profit										6.50%
Percentage of net profit for subsequent borrowing										2.50%
Minimum amount of NPI earned											1.5
Percentage of NPI earned				25.00%						1.00%
Amount of undeveloped leasehold in purchase and sale agreement				$ 15
Undeveloped leasehold, net acres				2,239
Percentage of over-riding royalty interest					1.50%	1.00%
Number of wells drilled in Marshall County, West Virginia				6
Terms of repurchase, undeveloped leasehold				American Shale sold (i) an undivided interest across all of its undeveloped leasehold amounting to approximately 2,239 net acres, (ii) an over-riding royalty interest of 1.5% in all of its leasehold in Wetzel County, West Virginia, and (iii) an over-riding royalty interest of 1.0% in six (6) wells that are currently being drilled in Marshall County, West Virginia. The consideration is to be paid in the form of a credit against expenses incurred by Republic on behalf of American Shale. American Shale reserved the right to receive 25% of the net profits earned by Republic on the assets sold by American Shale under the Republic PSA. American Shale has the option to repurchase the undivided interest across all of its undeveloped leasehold, plus the over-riding royalty interest in its Wetzel County leasehold, for $15 million if (i) such payment is made within six (6) months of the Funding Date, or (ii) a purchase and sale agreement that would allow for such repayment by American Shale is signed within such period and the transaction contemplated therein in closed prior to December 31, 2014.
Membership interest in purchase and sale agreement				25.00%												12.00%
Portion of future leasehold expenditures				50.00%