Fair Value Measurements - Fair Value Inputs, Liabilities, Quantitative Information (Details) (Contingent Consideration [Member], USD $) In Thousands, unless otherwise specified				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Income Approach Valuation Technique [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2011 Income Approach Valuation Technique [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2012 Minimum [Member] Income Approach Valuation Technique [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2011 Minimum [Member] Income Approach Valuation Technique [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2012 Maximum [Member] Income Approach Valuation Technique [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2011 Maximum [Member] Income Approach Valuation Technique [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2012 Revenue-based Payments [Member]	Dec. 31, 2011 Revenue-based Payments [Member]	Dec. 31, 2012 Other Payments [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Discount rate				4.50%		10.00%	10.00%	14.50%	14.50%
Contingent consideration liability	$ 6,697	$ 1,290	$ 0							$ 6,370	$ 1,290	$ 327
Probability of milestone payment				90.00%	90.00%