CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended				12 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011
Revenues (including amounts from related parties of $0 and $4,699 for the three months ended September 30, 2012 and 2011 and $0 and $13,882 for the nine months ended September 30, 2012 and 2011, respectively	$ 398,863	[1]	$ 340,098	[1]	$ 1,118,590	[1]	$ 980,247	[1]
Expenses:
Cost of revenues (exclusive of items shown separately below)	156,749		137,619		437,153		393,360
Selling, general and administrative	58,707		51,475		175,159		156,640
Depreciation and amortization of fixed assets	12,714		10,798		37,448		32,958
Amortization of intangible assets	15,442		8,797		36,216		26,129
Acquisition related liabilities adjustment							(3,364)
Total expenses	243,612		208,689		685,976		605,723
Operating income	155,251		131,409		432,614		374,524
Other income (expense):
Investment income	136		99		397		99
Realized (loss) gain on securities, net	(638)		(86)		(338)		401
Interest expense	(18,133)		(14,593)		(51,895)		(39,093)
Total other expense, net	(18,635)		(14,580)		(51,836)		(38,593)
Income before income taxes	136,616		116,829		380,778		335,931
Provision for income taxes	(53,705)		(45,842)		(149,935)		(133,491)
Net income	$ 82,911		$ 70,987		$ 230,843		$ 202,440		$ 282,758
Basic net income per share	$ 0.50		$ 0.43		$ 1.39		$ 1.21
Diluted net income per share	$ 0.48		$ 0.41		$ 1.34		$ 1.16
Weighted average shares outstanding:
Basic	165,978,080		164,195,325		165,587,027		166,728,786
Diluted	171,660,543		171,169,658		171,637,571		174,255,965

[1] See Note 13. Related Parties for further information.