CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 18,941	$ 42,860	$ 70,930	$ 149,933
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	6,173	6,930	20,816	22,045
Provision for doubtful accounts	17,967	22,873	56,890	57,480
Deferred income taxes	280	(6,021)	16,614	(16,097)
Excess tax benefit from stock option exercises	0	(3)	0	(1,382)
Stock-based compensation expense	3,304	4,291	8,698	13,046
Settlement cost	0	0	(46,000)	0
Other	102	340	467	97
Changes in operating assets and liabilities, net of acquisition:
Restricted cash	164	31	(11)	1,408
Accounts receivable	(13,326)	(38,623)	(98,012)	(98,799)
Accounts payable	(2,427)	(4,419)	(2,012)	(2,518)
Other operating assets and liabilities	2,370	(5,758)	(8,634)	1,008
Deferred revenue	17,769	(2,784)	(4,240)	(107,454)
Net cash flows from operating activities	51,317	19,717	15,506	18,767
Cash flows from investing activities:
Facility expenditures	(81)	(108)	(541)	(493)
Capital expenditures, net	(904)	(3,185)	(4,277)	(14,820)
Acquisition of company, net of cash acquired	(6,953)	0	(6,953)	0
Proceeds from sales and maturities of investments and repayment of notes	91	553	413	216,724
Purchase of investments and note advances	(138)	0	(1,379)	(63,545)
Net cash flows from investing activities	(7,985)	(2,740)	(12,737)	137,866
Cash flows from financing activities:
Excess tax benefit from stock option exercises	0	3	0	1,382
Proceeds from exercise of stock options	0	254	0	8,345
Debt issue costs	0	0	0	(1,525)
Proceeds from revolving borrowings	0	0	0	175,000
Repayment of revolving borrowings	(60,000)	(10,000)	(80,000)	(185,000)
Repurchase of common stock and shares tendered for taxes	(19)	(10)	(390)	(209,370)
Net cash flows from financing activities	(60,019)	(9,753)	(80,390)	(211,168)
Net change in cash and cash equivalents	(16,687)	7,224	(77,621)	(54,535)
Cash and cash equivalents at beginning of period	185,408	167,234	246,342	228,993
Cash and cash equivalents at end of period	$ 168,721	$ 174,458	$ 168,721	$ 174,458