Consolidated Balance Sheets - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Current assets:    
Cash and cash equivalents $ 44,656 $ 23,515
Accounts receivable, net of allowance for doubtful accounts of $5,344 and $3,745 at June 30, 2018 and December 31, 2017, respectively 393,300 309,733
Income taxes receivable 4,360 5,101
Prepaid expenses 8,090 6,191
Other current assets 4,793 3,760
Total current assets 455,200 348,301
Noncurrent assets:    
Property and equipment, net of accumulated depreciation of $97,857 and $86,549 at June 30, 2018 and December 31, 2017, respectively 63,219 63,062
Goodwill 307,314 307,314
Intangible assets, net of accumulated amortization of $63,309 and $56,834 at June 30, 2018 and December 31, 2017, respectively 111,009 117,484
Other noncurrent assets 3,039 1,918
Total noncurrent assets 484,580 489,778
Total assets 939,780 838,079
Current liabilities:    
Accounts payable 267,278 193,749
Due to seller, current 1,250 919
Accrued expenses 43,206 39,660
Total current liabilities 311,734 234,328
Noncurrent liabilities:    
Convertible notes, net 214,774 210,919
Due to seller, noncurrent 0 1,156
Other noncurrent liabilities 19,239 20,301
Deferred income taxes 15,816 12,503
Total noncurrent liabilities 249,829 244,879
Total liabilities 561,563 479,207
Stockholders' equity:    
Common stock, par value $0.0001 per share, 100,000,000 shares authorized, 31,243,465 shares issued and 27,716,595 shares outstanding at June 30, 2018; 30,768,050 shares issued and 27,241,180 shares outstanding at December 31, 2017 3 3
Treasury stock, 3,526,870 shares at June 30, 2018 and December 31, 2017, respectively (69,818) (69,818)
Additional paid-in capital 343,249 337,445
Retained earnings 104,783 91,242
Total stockholders' equity 378,218 358,872
Total liabilities and stockholders' equity $ 939,780 $ 838,079