XML 34 R23.htm IDEA: XBRL DOCUMENT v3.2.0.727
Cash and Investments in Marketable Securities - Portfolio of Cash and Investments in Marketable Securities (Detail) - USD ($)
$ in Thousands
Jun. 30, 2015
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale investments $ 230,856 $ 225,459
Cash, including restricted cash 29,363 26,136
Total cash and investments in marketable securities 279,660 262,824
Corporate Notes and Bonds [Member] | Fair Value Hierarchy Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale investments 185,917 182,544
Corporate Commercial Paper [Member] | Fair Value Hierarchy Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale investments 44,939 42,915
Money Market Funds [Member] | Fair Value Hierarchy Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in marketable securities 16,512 11,229
Certificates of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in marketable securities $ 2,929 $ 0