Note 8 - Fair Value Measurements (Detail) - Financial Assets Measured at Fair Value on a Recurring Basis: (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Marketable securities	$ 251,015		$ 317,855
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable securities	99,477		309,780
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member]
Marketable securities	99,477	[1]	309,780	[1]
US Treasury Securities [Member]
Marketable securities	99,477		309,779
Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable securities	20,117
Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
Marketable securities	20,117	[1]
Corporate Securities [Member]
Marketable securities	20,117
Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable securities	22,291
Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member]
Marketable securities	22,291	[1]
Commercial Paper [Member]
Marketable securities	22,291
Corporate Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable securities	46,931		1,521
Corporate Obligations [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Marketable securities	1,783
Corporate Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Marketable securities	48,714	[1]	1,521	[1]
Corporate Obligations [Member]
Marketable securities	48,714		1,521
US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable securities			3,526
US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Marketable securities			3,526	[1]
US Government Agencies Debt Securities [Member]
Marketable securities			3,526
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Cash, including short-term deposits	80,085		8,601
Total	199,679		321,907
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Total	69,222		1,521
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Non-controlling interests in certain funds	1,021		1,117
Total	2,804		1,117
Rogue contingent consideration	(475)		(1,218)
Fair Value, Measurements, Recurring [Member]
Cash, including short-term deposits	80,085	[2]	8,601	[3]
Non-controlling interests in certain funds	1,021	[4]	1,117	[4]
Total	271,705		324,545
Rogue contingent consideration	$ (475)	[5]	$ (1,218)	[6]

[1] Recorded within "Marketable securities."

[2] At December 31 2012, the Company recorded $68.2 million and $11.9 million within "Cash and cash equivalents" and "Marketable securities," respectively.

[3] At December 31 2011, the Company recorded $8.5 million and $0.1 million within "Cash and cash equivalents" and "Marketable securities," respectively.

[4] Recorded within "Other long-term assets."

[5] Recorded within "Accrued expenses and other liabilities."

[6] Recorded within "Accrued expenses and other liabilities.