Convertible Debt (Tables)

6 Months Ended

Jun. 30, 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						Six Months Ended
	June 30,						June 30,
	2013			2012			2013			2012
Effective interest rate of 2013 convertible senior notes	NA			3.73		%	3.73		%	3.73		%
Effective interest rate of 2015 convertible senior notes	4.50		%	NA			4.50		%	NA
Contractually stated interest costs	$	202		$	309		$	463		$	618
Amortization of issuance costs	$	11		$	111		$	39		$	221