ACQUISITIONS (Details) (USD $)					3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Prisma	Oct. 02, 2012 Prisma	Mar. 31, 2013 Prisma Minimum	Mar. 31, 2013 Prisma Maximum
Acquisitions
Initial cash consideration transferred				$ 200,000,000
Fair Value of Assets Acquired and Liabilities Assumed:
Fair Value of Contingent Consideration	81,600,000	71,300,000	81,600,000
Present value of undiscounted cash flows					$ 0	$ 155,000,000
Discount rate (as a percent)					2.10%	3.10%