Financial Instruments and Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities (Note 5), Fair Value	$ 3,001	[1]	$ 119,391	[2]
Marketable securities (Note 5), Carrying Amount	$ 3,001

[1] Included in current marketable securities at June 30, 2013.

[2] Included in current marketable securities at December 31, 2012.