Fair Value Measurements - Financial assets measured at fair value on a recurring basis (Detail) (USD $) | Sep. 30, 2013 | Dec. 31, 2012 |
In Thousands, unless otherwise specified |
Cash, including short-term deposits [Member] | ' | | ' | |
Financial Assets | $120,214 | [1] | $68,265 | [1] |
Cash, including short-term deposits [Member] | Cash And Cash Equivalent [Member] | ' | | ' | |
Financial Assets | ' | | 68,200 | |
Cash, including short-term deposits [Member] | Marketable Securities [Member] | ' | | ' | |
Financial Assets | ' | | 100 | |
Cash, including short-term deposits [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 120,214 | [1] | 68,265 | [1] |
Cash, including short-term deposits [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 0 | [1] | 0 | [1] |
Cash, including short-term deposits [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 0 | [1] | 0 | [1] |
Mutual Funds [Member] | ' | | ' | |
Financial Assets | 16,129 | [2] | 11,820 | [2] |
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 16,129 | [2] | 11,820 | [2] |
Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 0 | [2] | 0 | [2] |
Mutual Funds [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 0 | [2] | 0 | [2] |
US Treasury and Government [Member] | ' | | ' | |
Financial Assets | 50,412 | [2] | 99,477 | [2] |
US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 50,412 | [2] | 99,477 | [2] |
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 0 | [2] | 0 | [2] |
US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 0 | [2] | 0 | [2] |
Corporate Securities [Member] | ' | | ' | |
Financial Assets | 73,970 | [2] | 20,117 | [2] |
Corporate Securities [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 67,922 | [2] | 20,117 | [2] |
Corporate Securities [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 0 | [2] | 0 | [2] |
Corporate Securities [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 6,048 | [2] | 0 | [2] |
Commercial Paper [Member] | ' | | ' | |
Financial Assets | 6,298 | [3] | 22,291 | [4] |
Commercial Paper [Member] | Cash And Cash Equivalent [Member] | ' | | ' | |
Financial Assets | 1,700 | | 3,400 | [2] |
Commercial Paper [Member] | Marketable Securities [Member] | ' | | ' | |
Financial Assets | 4,600 | | 18,900 | [2] |
Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 0 | [3] | 0 | [4] |
Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 6,298 | [3] | 22,291 | [4] |
Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 0 | [3] | 0 | [4] |
Corporate Obligations [Member] | ' | | ' | |
Financial Assets | 24,386 | [2] | 48,714 | [2] |
Corporate Obligations [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 0 | [2] | 0 | [2] |
Corporate Obligations [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 12,573 | [2] | 46,931 | [2] |
Corporate Obligations [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 11,813 | [2] | 1,783 | [2] |
Non-controlling interests in certain funds [Member] | ' | | ' | |
Financial Assets | 849 | [5] | 1,021 | [6] |
Non-controlling interests in certain funds [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 0 | [5] | 0 | [6] |
Non-controlling interests in certain funds [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 0 | [5] | 0 | [6] |
Non-controlling interests in certain funds [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 849 | [5] | 1,021 | [6] |
Financial Assets [Member] | ' | | ' | |
Financial Assets | 292,258 | | 271,705 | |
Financial Assets [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Assets | 254,677 | | 199,679 | |
Financial Assets [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Assets | 18,871 | | 69,222 | |
Financial Assets [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Assets | 18,710 | | 2,804 | |
Acquisition-related contingent consideration [Member] | ' | | ' | |
Financial Liabilities | ' | | -475 | [7] |
Acquisition-related contingent consideration [Member] | Fair Value, Inputs, Level 1 [Member] | ' | | ' | |
Financial Liabilities | ' | | 0 | [7] |
Acquisition-related contingent consideration [Member] | Fair Value, Inputs, Level 2 [Member] | ' | | ' | |
Financial Liabilities | ' | | 0 | [7] |
Acquisition-related contingent consideration [Member] | Fair Value, Inputs, Level 3 [Member] | ' | | ' | |
Financial Liabilities | ' | | ($475) | |
|
[1] | Reported within "Cash and cash equivalents". |
[2] | Reported within bMarketable securitiesb |
[3] | At September 30, 2013, the Company reported $1.7 million and $4.6 million within "Cash and cash equivalents" and "Marketable securities", respectively. |
[4] | At December 31, 2012, the Company reported $3.4 million and $18.9 million within "Cash and cash equivalents" and "Marketable securities." |
[5] | Reported within "Other investments". |
[6] | Reported within "Other investments" |
[7] | Reported within bAccrued expensesb. |