FAIR VALUE MEASUREMENTS - Fair Value Measurements (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets:
Cash and cash equivalents	$ 12,722	$ 31,324
Short-term investments	479	503
Total assets	13,201	31,827
Liabilities:
Contingent consideration	15,807	18,511
Total liabilities	15,807	18,511
Level 1 Inputs
Assets:
Cash and cash equivalents	12,722	31,324
Short-term investments	479	503
Total assets	13,201	31,827
Liabilities:
Contingent consideration	0	0
Total liabilities	0	0
Level 2 Inputs
Assets:
Cash and cash equivalents	0	0
Short-term investments	0	0
Total assets	0	0
Liabilities:
Contingent consideration	0	0
Total liabilities	0	0
Level 3 Inputs
Assets:
Cash and cash equivalents	0	0
Short-term investments	0	0
Total assets	0	0
Liabilities:
Contingent consideration	15,807	18,511
Total liabilities	$ 15,807	$ 18,511