Income Taxes (Tables)

9 Months Ended

Sep. 30, 2011

Income Tax Disclosure [Abstract]

Schedule of provision for income taxes

The provision for income taxes consists of the following:

	For the Three Months Ended September 30,						For the Nine Months Ended September 30,
	2011			2010			2011			2010
	(in thousands)
Current portion of income tax expense:
Federal	$	20,699		$	2,194		$	29,855		$	10,410
State	637			277			1,036			588
Deferred portion of income tax expense	112,010			6,875			164,251			85,695
Total income tax expense	$	133,346		$	9,346		$	195,142		$	96,693
Effective tax rate	36.7		%	37.7		%	36.7		%	37.7		%