Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Schedule Of Change In Asset Retirement Obligation

	Asset Retirement Obligation
Balance, December 31, 2011	$	1,845
Additional asset retirement obligation		11
Accretion expense		28
Settlements		(75	)
Balance, March 31, 2012	$	1,809