Fair Value of Financial Instruments - Level 3 (Details) (Fair Value, Inputs, Level 3 [Member], USD $) In Thousands, unless otherwise specified			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Change in estimate	Mar. 31, 2013 Accretion Expense [Member]	Mar. 31, 2013 Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Short-Term Portion of Contingent Consideration [Member]	Mar. 31, 2013 Long-Term Portion of Contingent Consideration [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration liability					$ (1,801)	$ (2,541)	$ 700	$ 1,100
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at December 31, 2012	1,801	2,541
Fair value level 3 activity			(803)	63
Balance at March 31, 2013	$ 1,801	$ 2,541