Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 30,457	$ 5,408	$ 2,869
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property and equipment	12,994	9,547	7,581
Amortization of capitalized in-vehicle devices owned by customers	960	668	344
Amortization of intangible assets	2,290	2,332	3,349
Amortization of deferred commissions, other deferred costs and debt discount	6,961	4,986	3,855
Provision for (benefit from) deferred tax assets	866	6,528	1,788
Provision for accounts receivable allowances	1,601	1,509	990
Unrealized foreign currency transaction (gain) loss	1,085	38	(178)
Loss on disposal of property and equipment and other assets	3,086	2,182	954
Share-based compensation	7,470	2,422	2,292
Loss on extinguishment of debt, non-cash portion		405
Changes in operating assets and liabilities, net of effects of acquisition:
Accounts receivable	(12,955)	(4,979)	(3,460)
Prepaid expenses and other current and long-term assets	(11,526)	(11,630)	(7,211)
Accounts payable, accrued expenses and other current liabilities	10,726	963	2,194
Excess (reversal of) tax benefits from share-based awards	(3,813)	266
Accrued income taxes	(12,465)	(3,266)	(1,015)
Deferred revenue	4,174	(489)	(12,547)
Net cash provided by (used in) operating activities	41,911	16,890	1,805
Cash flows from investing activities:
Purchases of property and equipment	(34,173)	(25,221)	(15,083)
Capitalization of internal-use software costs	(2,225)	(883)	(686)
Payment for acquisition, net of cash acquired	(6,786)
Net increase (decrease) in restricted cash		528	(387)
Net cash used in investing activities	(43,184)	(25,576)	(16,156)
Cash flows from financing activities:
Proceeds from (payments of) Term Loan	(938)	23,549
Proceeds from exercise of stock options	5,517	305
Proceeds from borrowings under Revolving Credit Facility		8,286
Payments of borrowings under Revolving Credit Facility		(8,286)
Excess (reversal of) tax benefits from share-based awards	3,813	(266)
Collection of note receivable from officer			152
Payments of Senior Secured Notes		(17,500)
Payments of previously accrued initial public offering costs	(1,355)
Payments of capital lease obligations	(437)	(369)	(139)
Net cash provided by financing activities	38,660	100,386	13
Effect of exchange rate changes on cash	(303)	(228)	(101)
Net increase (decrease) in cash	37,084	91,472	(14,439)
Cash, beginning of period	100,087	8,615	23,054
Cash, end of period	137,171	100,087	8,615
Supplemental disclosure of cash flow information:
Cash paid for interest	1,262	1,913	2,251
Cash paid for income taxes	4,555	1,841	243
Supplemental disclosure of non-cash financing and investing activities:
Accretion of redeemable convertible preferred shares to redemption value		335	446
Acquisition of property and equipment through capital leases	427	31	1,152
Additions to property and equipment included in accounts payable at the balance sheet dates	1,416	2,173	1,276
Initial public offering costs included in accounts payable at the balance sheet dates		1,354
Issuance of ordinary shares under employee share purchase plan	283
Initial public offering
Cash flows from financing activities:
Proceeds from public offering, net of offering costs		94,667
Secondary Public Offering
Cash flows from financing activities:
Proceeds from public offering, net of offering costs	$ 32,060