CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 214,386	$ 114,034
Short-term investments	498,935	614,130
Accounts receivable (net of allowances of $2,096 and $1,022 at September 30, 2016 and December 31, 2015, respectively)	79,894	81,305
Prepaid expenses and other current assets	8,767	16,162
Income tax receivable	11,806	18,377
Total current assets	813,788	844,008
Non-current assets:
Property, equipment and capitalized software, net	70,379	65,031
Goodwill	133,570	137,733
Intangible assets, net	56,429	61,855
Other assets	2,846	4,250
Total assets	1,077,012	1,112,877
Current liabilities:
Accounts payable	13,890	21,136
Accrued compensation	16,687	13,538
Other current liabilities	4,824	11,444
Deferred revenue	5,868	5,507
Deferred rent	977	797
Credit facilities	26,250	15,000
Capital lease obligation	112	109
Total current liabilities	68,608	67,531
Non-current liabilities:
Credit facilities, less current portion	243,750	266,250
Capital lease obligation, less current portion	242	296
Deferred rent	1,709	2,446
Deferred income taxes	34,084	37,198
Total liabilities	348,393	373,721
Commitments and contingencies (Note 5)
Stockholders' equity:
Common stock
Preferred stock, $0.0001 par value, 100,000,000 shares authorized, zero shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively
Additional paid-in-capital	505,550	493,197
Retained earnings	273,963	247,540
Other comprehensive income (loss)	223	(1,582)
Total stockholders' equity	728,619	739,156
Total liabilities and stockholders' equity	1,077,012	1,112,877
Class A Common
Stockholders' equity:
Common stock
Treasury stock, at cost, 3,364,531 and zero shares at September 30, 2016 and December 31, 2015, respectively	(51,118)
Class B Common
Stockholders' equity:
Common stock	$ 1	$ 1