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				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Employee Stock Purchase Plan [Member]
[Line Items]
Shares of stock sold to employees(1)	20	[1]	27	[1]	34	[1]	47	[1]
Weighted average fair value per ESPP award(2)	$ 0.00	[2]	$ 6.37	[2]	$ 0.00	[2]	$ 6.69	[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 and six months ended June 30, 2014.