Convertible Debt (Tables)

3 Months Ended

Mar. 31, 2013

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

The following table outlines the effective interest rate, contractually stated interest costs, and costs related to the amortization of issuance costs for the Company's 2013 and 2015 convertible senior notes:

	Three Months Ended
	March 31,
	2013			2012
Effective interest rate of 2013 convertible senior notes	3.73		%	3.73		%
Effective interest rate of 2015 convertible senior notes	4.50		%	NA
Contractually stated interest costs	$	261		$	309
Amortization of issuance costs	$	28		$	110