Fair Value Measurements Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of January 1, 2013, other assets	$ 0
Balance as of January 1, 2013, other liabilities	(1,200)
Fair value adjustment to contingent consideration for acquisition of Verivue included in general and administrative expense	1,200
Convertible note receivable from divestiture of a business	18,882
Unrealized gain on convertible note receivable included in general and administrative expense	1,093
Balance as of June 30, 2013, other assets	19,975
Balance as of June 30, 2013, other liabilities	$ 0