Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2012

Accounting Policies [Abstract]

Net income for purposes of determining basic EPS

Net income for purposes of determining basic EPS was as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2012			2011			2012			2011
Net income (loss)	$	3,895		$	30,301		$	(3,795	)	$	49,674
Income (expense) attributable to participating securities	(79		)	(639		)	—			(1,033		)
Net income (loss) available to common stockholders	$	3,816		$	29,662		$	(3,795	)	$	48,641

Net income (loss) for purposes of determining diluted EPS

Net income (loss) for purposes of determining diluted EPS was as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2012			2011			2012			2011
Net income (loss)	$	3,895		$	30,301		$	(3,795	)	$	49,674
Income attributable to 3.875% Variable Interest Senior Convertible Debentures	—			(95		)	—			—
Expense attributable to 6.75% Variable Interest Senior Convertible Note	—			—			—			1,856
Income (expense) attributable to participating securities	(79		)	(637		)	—			(1,072		)
Net income (loss) available to common stockholders	$	3,816		$	29,569		$	(3,795	)	$	50,458

Basic and diluted EPS calculation shares

Basic and diluted EPS were calculated using the following shares:

	Three Months Ended		Six Months Ended
	June 30,		June 30,
	2012	2011	2012	2011
Weighted-average shares for basic EPS	79,376,192	78,394,709	79,218,365	78,305,932
Plus incremental shares related to stock options and non-vested restricted stock	193,446	659,393	—	470,702
Plus incremental shares related to convertible debt	—	6,728,285	—	3,848,489
Weighted-average shares for fully diluted EPS	79,569,638	85,782,387	79,218,365	82,625,123

Outstanding shares not included in the computation of diluted EPS

The following stock options, non-vested restricted stock and shares issuable upon the conversion of convertible debt were outstanding during the three and six months endedJune 30, 2012 and 2011 but were not included in the computation of diluted EPS because the effect was anti-dilutive.

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2012		2011		2012		2011
Number of stock options	N/A		157,278		2,190,133		163,772
Weighted-average exercise price	N/A		$	23.69	$	13.74	$	23.42
Weighted-average shares of non-vested restricted stock	3,334		N/A		365,321		N/A
Weighted-average expense per share	17.98		N/A		11.40		N/A
Weighted-average number of shares issuable upon   conversion of debt	17,004,017		11,144,039		17,159,342		14,087,525
Weighted-average conversion price	$	14.79	$	14.13	$	14.80	$	15.43