Income Taxes (Details 2) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Income Tax Disclosure [Abstract]
Amount computed using the statutory rate	$ 5,041		$ (45,655)		$ 3,058
State & local taxes	317		(2,870)		192
Percentage depletion carryforward	(1,323)		(1,309)		(2,507)
Allowance for alternative minimum tax	0		0		8
Non-deductible stock option expense	115	[1]	292	[1]	183	[1]
Share-based compensation	780	[2]	9	[2]	346	[2]
Other	1,132		303		(300)
Change in valuation allowance	(5,742)		50,866		(2,790)
Income tax expense (benefit)	$ 320		$ 1,636		$ (1,810)

[1] Relates to compensation expense recognized on the vesting of Incentive Stock Options.

[2] Relates to the write-off of deferred tax assets associated with share based compensation that will not be recognized for tax purposes.