Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock: Class A Common Stock, Class B Common Stock and Class C Capital Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2013	$ 567,796	$ 12	$ 651,905	$ (84,121)
Beginning Balance (in shares) at Dec. 31, 2013		118,208,898
Issuance of common and capital stock upon exercise of stock options	23,923		23,923
Issuance of common and capital stock upon exercise of stock options (in shares)		3,970,527
Issuance of common and capital stock related to vesting of restricted stock units		208,095
Share-based compensation expense	40,670		40,670
Net loss	(43,610)			(43,610)
Ending Balance at Dec. 31, 2014	588,779	$ 12	716,498	(127,731)
Ending Balance (in shares) at Dec. 31, 2014		122,387,520
Issuance of common and capital stock in connection with an acquisition	1,883,728	$ 5	1,883,723
Issuance of common and capital stock in connection with an acquisition (in shares)		51,779,112
Equity award vesting acceleration in connection with restructuring	14,859		14,859
Fair value of equity awards assumed in connection with an acquisition	82,840		82,840
Debt premium recorded in additional paid-in capital in connection with an acquisition	126,386		126,386
Issuance of common and capital stock upon exercise of stock options	24,423	$ 1	24,422
Issuance of common and capital stock upon exercise of stock options (in shares)		2,732,767
Issuance of common and capital stock related to vesting of restricted stock units		1,899,531
Shares and value of restricted stock units withheld for tax liability	(8,150)		(8,150)
Shares and value of restricted stock units withheld for tax liability (in shares)		(324,013)
Share-based compensation expense	115,533		115,533
Net loss	(148,874)			(148,874)
Other comprehensive income (loss)	(471)				$ (471)
Ending Balance at Dec. 31, 2015	2,679,053	$ 18	2,956,111	(276,605)	(471)
Ending Balance (in shares) at Dec. 31, 2015		178,474,917
Issuance of common and capital stock upon exercise of stock options	31,211		31,211
Issuance of common and capital stock upon exercise of stock options (in shares)		2,518,172
Issuance of common and capital stock related to vesting of restricted stock units		1,487,263
Shares and value of restricted stock units withheld for tax liability	(616)		(616)
Shares and value of restricted stock units withheld for tax liability (in shares)		(21,634)
Share-based compensation expense	116,979		116,979
Portion of repurchase price recorded in additional paid-in capital in connection with partial repurchase of 2020 Notes	(127,615)		(127,615)
Equity component of issuance of 2021 Notes, net of issuance costs of $2,494	91,400		91,400
Premiums paid for Capped Call Confirmations	(36,616)		(36,616)
Net loss	(220,438)			(220,438)
Other comprehensive income (loss)	229				229
Ending Balance at Dec. 31, 2016	$ 2,533,587	$ 18	$ 3,030,854	$ (497,043)	$ (242)
Ending Balance (in shares) at Dec. 31, 2016		182,458,718