FAIR VALUE MEASUREMENTS (Details) (USD $)	3 Months Ended						3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Carrying value	Dec. 31, 2013 Carrying value	Mar. 31, 2014 Level 2 Fair value	Dec. 31, 2013 Level 2 Fair value	Mar. 31, 2014 Recurring Fair value	Dec. 31, 2013 Recurring Fair value	Mar. 31, 2014 Recurring Level 1	Dec. 31, 2013 Recurring Level 1	Mar. 31, 2014 Recurring Level 3	Dec. 31, 2013 Recurring Level 3
Assets
Cash equivalents							$ 20,676,000	$ 33,524,000	$ 20,676,000	$ 33,524,000
Total assets							20,676,000	33,524,000	20,676,000	33,524,000
Liabilities
Acquisition-related contingent considerations							597,000				597,000	586,000
Total liabilities							597,000	586,000			597,000	586,000
Change in acquisition-related contingent consideration liabilities
Balance at the beginning of the period							586,000				597,000	586,000
Amortization of present value discount	(18,000)	(19,000)					18,000
Fair value adjustment for change in consideration expected to be paid							(7,000)
Balance at the end of the period							597,000				597,000	586,000
Notes			$ 559,400,000	$ 558,800,000	$ 643,400,000	$ 634,800,000