Correction of Immaterial Errors (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable, net	$ 63,345	$ 57,189
Other receivables	4,474	5,688
Prepaid expenses and other current assets	7,102	7,675
Accounts payable	29,934	23,482
Accrued expenses	7,308	9,366
Retained earnings	79,968	78,467
Total stockholders' equity	$ 83,291	81,273	$ 67,347	$ 66,488
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable, net		56,003
Other receivables		5,104
Prepaid expenses and other current assets		7,224
Accounts payable		22,453
Accrued expenses		8,977
Retained earnings		77,664
Total stockholders' equity		80,470
Adjustments | Recognition of Certain Income and Expenses
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable, net		1,186
Other receivables		584
Prepaid expenses and other current assets		451
Accounts payable		1,029
Accrued expenses		389
Retained earnings		803
Total stockholders' equity		$ 803