Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net income (loss)	$ 269	$ (18,776)	$ (26,983)
Adjustments to reconcile net loss including non-controlling interests to net cash provided by operating activities:
Depreciation and amortization of property and equipment	78,837	69,097	49,202
Amortization of intangible assets	3,710	3,498	3,448
Bad debt expense	363	773	116
Impairment loss and loss on disposal of fixed assets, net	238	1,158	66
Stock-based compensation	12,268	14,215	12,805
Amortization of deferred financing costs and debt discount, net of amounts capitalized	2,261	86	182
Change in deferred income taxes	(5,617)	(2,575)	303
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	(13,702)	16,046	526
Prepaid expenses and other assets	(800)	(841)	(835)
Accounts payable	(246)	(1,554)	(465)
Accrued expenses and other liabilities	6,477	9,313	5,835
Deferred revenue	9,263	7,288	71,005
Net cash provided by operating activities	93,321	97,728	115,205
Cash flows from investing activities
Purchases of property and equipment	(108,730)	(73,308)	(107,271)
Payments for asset and business acquisitions	(24,624)	(1,150)	(60)
Net cash used in investing activities	(133,354)	(74,458)	(107,331)
Cash flows from financing activities
Proceeds from Convertible Notes offering, net of issuance costs	195,716	0	0
Payment for capped call options	(23,969)	0	0
Proceeds from credit facility	15,000	0	5,000
Principal payments on credit facility	(15,875)	(16,094)	(5,656)
Proceeds from exercise of stock options	9,979	9,244	2,984
Payments of capital leases and notes payable	(6,181)	(4,207)	(2,212)
Payments of withholding tax on net issuance of restricted stock units	(10,536)	(4,872)	(2,827)
Debt issuance costs	(695)	0	(124)
Payments to non controlling interest	(614)	(125)	(286)
Net cash provided by (used in) financing activities	162,825	(16,054)	(3,121)
Effect of exchange rates on cash	(65)	(16)	14
Net increase in cash and cash equivalents	122,727	7,200	4,767
Cash and cash equivalents at beginning of year	26,685	19,485	14,718
Cash and cash equivalents at end of year	149,412	26,685	19,485
Supplemental disclosure of cash flow information
Cash paid for interest, net of amounts capitlized	0	239	0
Cash paid for taxes, net of refunds	565	304	163
Supplemental disclosure of non-cash investing and financing activities
Property and equipment costs included in accounts payable, accrued expenses and other liabilities	37,275	20,554	16,976
Purchase of equipment and prepaid maintenance services under capital financing arrangements	5,068	7,944	6,629
Capitalized stock-based compensation included in property and equipment costs	789	696	727
Purchase price for asset and business acquisitions included in accrued expenses and other liabilities	4,913	0	1,150
Debt issuance costs included in accrued expenses and other liabilities	164	0	0
Tax effect on equity component of Convertible Notes	$ 5,686	$ 0	$ 0