INVESTMENTS - Cost and Fair Value of Debt Investments Based on Maturities (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Available For Sale Securities Debt Maturities [Abstract]
Due in one year or less, Amortized Costs	$ 43,282	$ 35,480
Due within two years, Amortized Costs	14,944
Total, Amortized Costs	58,226	35,480
Due in one year or less, Fair Value	43,259	35,470
Due within two years, Fair Value	14,919
Total, Fair Value	$ 58,178	$ 35,470