Consolidated Balance Sheets - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 43,518,677	$ 56,522,194
Accounts receivable, net of allowance for doubtful accounts of $1,403,858 and $1,627,315 at March 31, 2016 and December 31, 2015, respectively	208,990,671	196,420,614
Income taxes receivable	1,528,262	1,038,327
Prepaid expenses	3,512,189	3,605,602
Other current assets	3,288,483	3,237,227
Total current assets	260,838,282	260,823,964
Noncurrent assets:
Property and equipment, net	28,085,153	27,304,474
Goodwill	307,314,171	308,490,588
Intangible assets, net of accumulated amortization of $30,784,159 and $26,785,810 at March 31, 2016 and December 31, 2015, respectively	143,533,820	147,532,169
Other noncurrent assets	2,986,788	2,358,587
Total noncurrent assets	481,919,932	485,685,818
Total assets	742,758,214	746,509,782
Current liabilities:
Accounts payable	116,403,035	103,985,783
Due to seller, current	843,842	2,338,462
Accrued expenses	28,020,457	30,283,062
Other current liabilities	0	784,829
Total current liabilities	145,267,334	137,392,136
Noncurrent Liabilities:
Convertible notes, net	198,344,843	196,659,354
Due to seller, noncurrent	1,004,230	1,748,235
Other noncurrent liabilities	5,316,566	2,940,435
Deferred income taxes	12,166,979	12,520,048
Total noncurrent liabilities	216,832,618	213,868,072
Total liabilities	362,099,952	351,260,208
Stockholders' equity:
Common stock, par value $0.0001 per share, 100,000,000 shares authorized, 29,941,529 shares issued and 28,992,684 shares outstanding at March 31, 2016; 29,765,525 shares issued and 29,727,588 shares outstanding at December 31, 2015	2,997	2,979
Treasury stock, 948,845 and 37,937 shares at March 31, 2016 and December 31, 2015, respectively	(19,390,803)	(784,829)
Additional paid-in capital	322,754,287	319,002,254
Retained earnings	77,291,781	77,029,170
Total stockholders' equity	380,658,262	395,249,574
Total liabilities and stockholders' equity	$ 742,758,214	$ 746,509,782