FAIR VALUE MEASUREMENTS (Details 1) (USD $)				3 Months Ended				3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Jan. 04, 2013 Twoo [Member]	Mar. 31, 2013 Auction rate security	Sep. 30, 2011 Auction rate security	Dec. 31, 2012 Auction rate security	Dec. 31, 2011 Auction rate security	Mar. 31, 2013 Contingent Consideration Arrangement	Mar. 31, 2012 Contingent Consideration Arrangement
Assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Fair Value of Contingent ConsideratonIncrease due to Interest Accretion			$ 1,500,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings								1,458,000
Changes in assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at the beginning of the period, assets				8,100,000			5,870,000
Total net gains (losses) (realized and unrealized) included in other comprehensive income, assets				480,000	1,850,000
Balance at the end of the period, assets				8,580,000	7,720,000		5,870,000
Changes in liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at the beginning of the period, liabilities									(10,000,000)
Fair value at date of acquisition, liabilities								(40,837,000)
Settlements, liabilities									10,000,000
Balance at the end of the period, liabilities								(42,295,000)
Auction rate securities
Cost basis				10,000,000
Gross unrealized losses	0	0		1,400,000		1,900,000
Fair Value of continegent consideration discount ratefor risk			15.00%
Business Acquisition, Contingent Consideration, at Fair Value, Current			1,300,000
Business Acquisition, Contingent Consideration, at Fair Value, Noncurrent			$ 41,000,000