Stock-Based Compensation Employee Stock Purchase Plan (Details) (Employee Stock Purchase Plan [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Employee Stock Purchase Plan [Member]
[Line Items]
Shares of stock sold to employees(1)	14	[1]	20	[1]
Weighted average fair value per ESPP award(2)	$ 0.00	[2]	$ 6.96	[2]

[1] Stock sold to employees during each fiscal quarter under the ESPP is associated with the offering period ending on the last day of the previous fiscal quarter.

[2] Effective October 1, 2013, the ESPP is no longer compensatory, and therefore the weighted average fair value per award is not applicable for the three months ended March 31, 2014.