Convertible Debt (Tables)

12 Months Ended

Dec. 31, 2012

Short-term Debt [Line Items]

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:

	Years Ended
	December 31,
	2012			2011			2010
Effective interest rate of 2013 convertible senior notes	3.73		%	3.64		%	3.64		%
Effective interest rate of 2015 convertible senior notes	4.50		%	NA			NA
Contractually stated interest costs	$	1,289		$	1,372		$	1,375
Amortization of interest costs	$	398		$	501		$	447

Convertible Senior Notes [Member]

Short-term Debt [Line Items]

Schedule of Debt [Table Text Block]

2013 Convertible Senior Notes

During February 2008, the Company offered and sold in a public offering pursuant to the shelf registration statement $55.0 million aggregate principal amount of 2.75% convertible senior notes due 2013 (the “2013 convertible senior notes”).

During the year ended December 31, 2012, the Company exchanged, in a private offering, $18.0 million aggregate principal amount of the 2013 convertible senior notes for $18.0 million aggregate principal amount of 4.50% convertible senior notes due 2015 (the “2015 convertible senior notes”). The Company accounted for the exchange in accordance with the relevant accounting guidance for debt exchanges and modifications. Refer below for further details of the 2015 convertible senior notes.

During the year ended December 31, 2012, the Company repurchased $10.1 million aggregate principal amount of the 2013 convertible senior notes, decreasing the aggregate principal amount of the 2013 senior convertible notes outstanding at December 31, 2012 to $16.9 million.

On February 15, 2013, the maturity date of the 2013 convertible senior notes, the Company repaid the entire outstanding aggregate principal balance of $16.9 million in accordance with the terms thereof.