Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:
Net loss	$ (10,216,000)	$ (14,939,000)	$ (8,333,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Gain on interest rate swap	(101,000)	(225,000)	(328,000)
Depreciation and amortization	62,748,000	58,551,000	47,439,000
Amortization of deferred rent	(370,000)	(82,000)	(450,000)
Share-based compensation	17,157,000	13,756,000	7,834,000
Excess tax benefit related to share-based compensation	(6,610,000)	(2,853,000)
Provision for doubtful accounts	4,751,000	2,852,000	2,297,000
Amortization of deferred financing costs	2,191,000	2,190,000	1,941,000
Deferred income taxes	(18,021,000)	(21,201,000)	(6,364,000)
Loss on early extinguishment of debt			621,000
Other		(31,000)
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	(31,112,000)	(24,666,000)	(9,047,000)
Prepaid expenses and other current assets	(552,000)	(64,000)	(1,801,000)
Accounts payable and accrued expenses	15,625,000	8,300,000	(1,907,000)
Accrued interest expense	(487,000)	671,000	10,240,000
Deferred revenue and customer deposits	1,676,000	2,425,000	(169,000)
Other liabilities	(324,000)	93,000	(2,430,000)
Net cash provided by operating activities	36,355,000	24,777,000	39,543,000
Investing activities:
Purchases of equipment and leasehold improvements, net	(6,544,000)	(5,841,000)	(6,856,000)
Cash paid for acquisitions, net	(3,318,000)	(108,970,000)	(322,248,000)
Working capital and other settlements for acquisitions	(569,000)	427,000	(6,710,000)
Proceeds from foreign currency net investment hedge	1,421,000
Other	(1,144,000)
Net cash used in investing activities	(10,154,000)	(114,384,000)	(335,814,000)
Financing activities:
Borrowings under senior secured revolving credit facility	142,473,000	170,640,000	278,000,000
Proceeds from the exercise of options and warrants	24,261,000	2,258,000	2,292,000
Excess tax benefit related to share-based compensation	6,610,000	2,853,000
Net borrowings (repayments) under working capital facilities	2,772,000	(6,279,000)	35,621,000
Borrowings under senior unsecured notes payable			250,000,000
Purchases of stock for treasury		(387,000)	(9,421,000)
Payment of deferred financing costs	(172,000)	(1,074,000)	(9,746,000)
Repayment of subordinated unsecured notes payable	(270,000)	(2,193,000)	(2,421,000)
Repayments under senior secured revolving credit facility	(196,746,000)	(76,000,000)	(273,000,000)
Other	(1,144,000)	(94,000)	(440,000)
Net cash provided by (used in) financing activities	(21,072,000)	89,724,000	270,885,000
Exchange rate impact on cash and cash equivalents	(927,000)	94,000	178,000
Net increase (decrease) in cash and cash equivalents	4,202,000	211,000	(25,208,000)
Cash and cash equivalents, beginning of year	8,627,000	8,416,000	33,624,000
Cash and cash equivalents, end of year	12,829,000	8,627,000	8,416,000
Supplemental disclosure of noncash investing and financing activities:
Issuance of common stock to settle earnout obligations			808,000
Supplemental disclosures of cash flow information:
Cash paid for interest	27,495,000	25,214,000	5,447,000
Cash paid for income taxes	8,967,000	8,913,000	4,061,000
Issuance Of Common Stock For Acquisitions [Member]
Supplemental disclosure of noncash investing and financing activities:
Issuance of common stock for acquisitions		$ 85,000	$ 47,174,000