Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2011

Long-Term Debt [Abstract]

Long-term debt

	2011		2010
2.0% Convertible Senior Notes due May 15, 2012	$	256,995	$	245,750
7.5% Senior Notes due November 15, 2019		400,000		—
Total long-term debt		656,995		245,750
Less current portion of 2.0% Convertible Senior Notes due May 15, 2012		256,995		—
Total long-term debt, less current portion	$	400,000	$	245,750

Amortization of the debt discount component and the contractual interest component for the 2.0% Convertible Senior Notes

	Years Ended December 31,
	2011		2010		2009
Interest expense:
Non-cash interest	$	11,361	$	10,646	$	9,974
Cash interest		5,199		5,200		5,200
Total interest expense	$	16,560	$	15,846	$	15,174