Exchangeable Senior Notes (Tables)

12 Months Ended

Dec. 31, 2011

Exchangeable Senior Notes [Abstract]

Additional Information About Senior Notes

	2010
Principal amount of liability component	$	140,000
Unamortized discount		(1,782	)
Carrying amount of liability component	$	138,218
Carrying amount of equity component	$	13,950

Additional Information About Senior Notes

	2011		2010		2009
Coupon interest	$	4,835	$	5,775	$	5,775
Issuance cost amortization		456		547		547
Discount amortization		1,782		2,082		1,968
Total interest expense	$	7,073	$	8,404	$	8,290