Fair Value Measurements (Schedule of Activity of Major Classes of Assets Measured at Fair Value Using Level 3 Inputs) (Details) (Level 3 [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013
Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of December 31, 2012	$ 0
Balance as of December 31, 2012	(1,200)
Fair value of note receivable	18,882
Fair value adjustment for contingent consideration for acquisition of Verivue	1,200
Balance as of March 31, 2013	18,882
Balance as of March 31, 2013	$ 0

Amount of increase (decrease) of assets measured at fair value on a recurring basis using unobservable inputs (level 3). Such increase (decrease) may be comprised of changes in fair value (gains or losses) whether realized or unrealized that have been included in earnings, changed net asset value, or other comprehensive income (a separate component of shareholders' equity); purchases, sales, issues, or settlements of assets; and net transfers in to or out of this category within the fair value hierarchy.

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Amount of increase (decrease) of liabilities measured at fair value on a recurring basis using unobservable inputs (level 3) which have taken place during the period. Such increase (decrease) may be comprised of changes in fair value (gains or losses) whether realized or unrealized that have been included in earnings, changed net asset value, or other comprehensive income (a separate component of shareholders' equity); purchases, sales, issues, or settlements of assets; and net transfers in to or out of this category within the fair value hierarchy.

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