Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets
Cash and cash equivalents	$ 121,579	$ 143,811
Marketable securities	43,808	34,031
Customer funds	5,262	1,999
Customer funds receivable	29,003	14,077
Accounts receivable, net of allowances of $6,843 and $4,558 as of June 30, 2013 and December 31, 2012, respectively	58,507	43,679
Deferred tax assets, net	4,412	4,412
Prepaid expenses and other current assets	26,641	19,142
Total current assets	289,212	261,151
Marketable securities - long-term		4,428
Property and equipment, net	31,289	27,407
Investments	121,666	122,808
Software and website developments costs, net	57,457	46,182
Intangible assets, net	114,282	117,599
Goodwill	278,142	270,646
Deferred tax assets, net	43,881	43,611
Other assets - long-term	13,379	16,684
Total assets	949,308	910,516
Current liabilities
Accounts payable	13,541	18,834
Accrued compensation and benefits	15,929	15,148
Accrued liabilities - other	22,438	16,870
Customer funds payable	34,265	16,076
Deferred revenue	8,474	7,959
Deferred tax liabilities	3,125	3,031
Due to acquirees	11,439	11,124
Total current liabilities	109,211	89,042
Deferred tax liabilities	76,898	77,368
Deferred revenue	5,724	5,525
Senior convertible notes, net	166,231	162,279
Other liabilities	3,636	4,985
Total long-term liabilities	252,489	250,157
Total liabilities	361,700	339,199
Commitments and contingencies (Note 15)
Stockholders' equity
Common stock, $0.01 par value: 175,000,000 shares authorized; 46,826,943 shares issued and 43,674,768 shares outstanding as of June 30, 2013; and 45,998,679 shares issued and 42,870,061 shares outstanding as of December 31, 2012	468	460
Treasury stock, at cost, 3,152,175 shares and 3,128,618 shares as of June 30, 2013 and December 31, 2012, respectively	(53,160)	(52,398)
Additional paid-in capital	558,590	541,948
Accumulated other comprehensive income	4,225	7,627
Retained earnings	77,485	73,680
Total stockholders' equity	587,608	571,317
Total liabilities and stockholders' equity	$ 949,308	$ 910,516