CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net income (loss)	$ (26,455)	$ 30,946
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	14,445	11,089
Amortization	44,562	39,644
Amortization of debt issuance costs	2,486	2,459
Impairment loss	2,778	1,799
Excess tax benefit from stock-based compensation	(7,970)	(28,167)
Stock-based compensation expense	25,169	20,906
Deferred income tax benefit, net	(13,702)	(1,236)
Provision for losses on accounts receivable	5,490	3,798
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(13,279)	(11,575)
Prepaid expenses and other current assets	263	(2,306)
Deposits and other assets	411	(68)
Accounts payable and other liabilities	30,085	24,712
Deferred revenue	5,433	4,035
Net cash provided by operating activities	69,716	96,036
Investing activities:
Proceeds from sale and settlement of investments	1,900	1,150
Purchases of property and equipment and other assets	(27,953)	(20,865)
Acquisitions, net of cash acquired	(177,476)	(584,218)
Net cash used in investing activities	(203,529)	(603,933)
Financing activities:
Proceeds from long-term debt	0	550,000
Payments of long-term debt	(15,000)	(313,125)
Payments of debt issuance costs	0	(9,969)
Payments of deferred consideration	0	(1,344)
Excess tax benefit from stock-based compensation	7,970	28,167
Repurchase of restricted stock to satisfy tax withholding obligations	(15,816)	(49,998)
Proceeds from equity offering, net of transaction costs	0	529,360
Proceeds from exercise of stock options and employee stock purchase plan	5,350	5,157
Net cash provided by (used in) financing activities	(17,496)	738,248
Effect of foreign currency exchange rates on cash and cash equivalents	(194)	(109)
Net increase (decrease) in cash and cash equivalents	(151,503)	230,242
Cash and cash equivalents at the beginning of period	527,012	255,953
Cash and cash equivalents at the end of period	$ 375,509	$ 486,195