Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Operating Activities:
Net income (loss)	$ 32,255	$ (1,386)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	37,620	27,475
Deferred tax benefit	(22,813)	(2,650)
Stock-based compensation expense	8,713	8,679
Provision for doubtful accounts and sales credits	4,828	4,015
Loss on sale of property and equipment		19
Amortization of deferred interest	15	68
Deferred compensation	150
Stock-based compensation windfall tax benefit	(2,255)	(1,398)
Realized gain on securities	(409)	(582)
Amortization of debt issuance costs	213
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(16,449)	(10,938)
Prepaid expenses and other current assets	(1,649)	(4,108)
Accounts payable and accrued expenses	(3,969)	(5,121)
Deferred revenue	1,726	115
Other liabilities - long-term	965	6
Deferred rent	37	89
Other assets - long-term	(223)	(11,408)
Net cash provided by operating activities	38,755	2,875
Investing Activities:
Capital expenditures	(6,860)	(9,669)
Sale of investments	2,935	1,420
Capitalized software and website development costs	(14,807)	(13,369)
Payment for acquisition of businesses and intangible assets, net of acquired cash	(151,962)	(3,028)
Net cash used in investing activities	(170,694)	(24,646)
Financing Activities:
Principal payments on capital lease obligations	(387)	(388)
Proceeds from the exercise of employee stock options	5,177	1,024
Proceeds from employee stock purchase plan	509	556
Purchase of treasury stock	(446)	(612)
Payment for debt issuance costs	(1,909)
Stock-based compensation windfall tax benefit	2,255	1,398
Net cash provided by financing activities	5,199	1,978
Net decrease in cash and cash equivalents	(126,740)	(19,793)
Effect of exchange rate changes on cash and cash equivalents	(872)	108
Cash and cash equivalents, beginning of period	192,563	197,509
Cash and cash equivalents, end of period	64,951	177,824
Supplemental Disclosure:
Income taxes	5,125	5,421
Interest	141	47
Non-cash investing and financing activities:
Consideration issued for acquisition of eCarList	12,956
Accrued capitalized hardware, software and fixed assets	1,756	2,697
Deferred compensation reversal to equity	150
Capitalized stock-based compensation	98	46
Assets acquired under capital leases	$ 34	$ 289