CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash Flows from Operating Activities
Net income (loss)	$ (23,149)	$ (173,811)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Loss from affiliates	522	0
Depreciation and amortization expenses	6,615	3,371
Goodwill impairment	0	160,600
Stock-based compensation expense	5,104	4,335
Amortization of deferred financing costs	405	(988)
Amortization of deferred financing costs	229	0
Accretion of bond premium/discounts	57	0
Accretion of bond premium/discounts	159	110
Changes in assets and liabilities, net of acquisitions:
Accounts receivables, net	(4,003)	(4,835)
Prepaid expenses and other current assets	(629)	656
Accounts payable, net of change in restricted cash and restricted investments	4,222	(2,896)
Accrued liabilities	(6,727)	1,414
Accrued compensation and employee benefits	(21,424)	(12,302)
Deferred revenue	4,581	3,494
Other long-term liabilities	(727)	48
Net cash provided by (used in) operating activities	(34,765)	(20,804)
Cash Flows from Investing Activities
Cash paid for asset acquisition or business combination	0	(11,500)
Maturities and sales of investments	10,600	0
Purchases of property and equipment	(5,978)	(3,353)
Change in restricted cash and restricted investments	0	1,198
Net cash provided by (used in) investing activities	4,622	(13,655)
Cash Flows from Financing Activities
Proceeds from stock option exercises	542	25
Taxes withheld for vesting of restricted stock units	(667)	0
Net cash provided by (used in) financing activities	(125)	25
Net increase (decrease) in cash and cash equivalents	(30,268)	(34,434)
Cash and cash equivalents as of beginning-of-period	134,563	145,726
Cash and cash equivalents as of end-of-period	104,295	111,292
Supplemental Disclosure of Non-cash Investing and Financing Activities
Accrued property and equipment purchases	83	90
Class A common stock issued in connection with business combinations	0	10,534
Measurement period adjustments related to business combinations	635	0
Change in accrued financing costs related to 2021 Notes	196	0
Effects of the March 2017 Secondary Offering
Decrease in non-controlling interests as a result of Class B Exchanges	$ 59,585	$ 0