CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities:
Net income	$ 280,440	$ 474,603	$ 425,560
Less: Discontinued operations, net of tax	(22,539)	148,262	120,063
Net income from continuing operations	302,979	326,341	305,497
Adjustments to reconcile net income from continuing operations to net cash provided by operating activities:
Depreciation of property and equipment, including internal-use software and website development	164,247	133,009	105,531
Amortization of stock-based compensation	64,596	63,847	52,507
Amortization of intangible assets	31,705	21,925	22,514
Deferred income taxes	(55,120)	9,942	19,181
Foreign exchange (gain) loss on cash, cash equivalents and short-term investments, net	(19,904)	17,525	20,988
Realized (gain) loss on foreign currency forwards	12,954	6,190	(8,822)
Other	17,521	14,807	(494)
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	(84,017)	(70,012)	(22,440)
Prepaid expenses and other current assets	(3,386)	(20,035)	82,733
Accounts payable, merchant	146,469	80,390	49,648
Accounts payable, other, accrued expenses and other current liabilities	345,938	65,152	3,213
Deferred merchant bookings	312,059	178,807	(24,679)
Deferred revenue	1,141	(2,159)	10
Net cash provided by operating activities from continuing operations	1,237,182	825,729	605,387
Investing activities:
Capital expenditures, including internal-use software and website development	(235,697)	(207,837)	(136,376)
Purchases of investments	(1,873,519)	(1,723,350)	(970,339)
Sales and maturities of investments	1,955,955	1,507,240	366,036
Acquisitions, net of cash acquired	(199,360)	(35,221)	(16,019)
Net settlement of foreign currency forwards	(12,954)	(6,190)	8,822
Other, net	(2,250)	1,898	3,529
Net cash used in investing activities from continuing operations	(367,825)	(463,460)	(744,347)
Financing activities:
Treasury stock activity	(417,571)	(294,027)	(501,993)
Payment of dividends to stockholders	(130,423)	(76,550)	(79,076)
Purchases of interest in controlled subsidiaries, net	(2,015)	(22,485)	(77,929)
Proceeds from issuance of long-term debt, net of issuance costs			742,470
Proceeds from exercise of equity awards	241,193	34,489	50,615
Excess tax benefit on equity awards	41,100	7,271	6,940
Other, net	(5,071)	(2,192)	(13,167)
Net cash provided by (used in) financing activities from continuing operations	(272,787)	(353,494)	127,860
Net cash provided by (used in) continuing operations	596,570	8,775	(11,100)
Net cash provided by (used in) discontinued operations	(7,607)	76,903	40,999
Effect of exchange rate changes on cash and cash equivalents	15,064	(17,743)	(19,880)
Net increase (decrease) in cash and cash equivalents	604,027	67,935	10,019
Cash and cash equivalents at beginning of year	689,134	621,199	611,180
Cash and cash equivalents at end of year	1,293,161	689,134	621,199
Supplemental cash flow information
Cash paid for interest from continuing operations	86,024	87,094	44,379
Income tax payments, net from continuing operations	$ 9,632	$ 53,772	$ 97,371