Acquisitions (Details 1) (USD $)	1 Months Ended		12 Months Ended
	Feb. 29, 2012 Unity	Feb. 03, 2012 Unity	Dec. 31, 2012 Other business acquisition Item Patent	Dec. 31, 2011 CRI	Jun. 03, 2011 CRI	Jun. 03, 2011 Favorable Contracts CRI
Retention bonus payable to Unity Employees		$ 5,000,000
Retention bonus payable to Unity employees (in years)	3 years
Related transaction costs		600,000		3,900,000
Cash		182,000			1,424,000
Accounts receivable					1,140,000
Property and equipment		51,000			965,000
Other tangible assets		36,000	1,000,000		133,000
Identified intangible assets		19,280,000	4,100,000		159,200,000	12,200,000
Goodwill		15,451,000	8,100,000		96,994,000
Liabilities					(2,613,000)
Total		35,000,000	13,200,000		257,243,000
Estimated average useful life (in years) for intangible assets	10 years		6 years
Number of businesses acquired			1
Number of patent and technology acquisitions			2
Retention bonus payable					$ 50,000,000