Income Taxes - Summery of Net Impact of the Tax Cuts and Jobs Act (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
U.S statutory income taxes rate	21.00%	35.00%	35.00%
Non-deductible expenses	(2.20%)	(6.80%)	(2.50%)
Foreign taxes rate differential	13.20%	15.10%	(14.20%)
Change in valuation allowance	(62.30%)	(11.90%)	(30.00%)
State income taxes	(4.50%)	18.70%	2.30%
Share based compensation	(4.50%)	(4.50%)	1.20%
Change in unrecognized taxes expense	0.30%	(0.80%)	(0.70%)
Other	0.70%	(71.90%)	0.40%
Effective taxes rate	(38.30%)	(27.10%)	(8.50%)
ETR before TCJA
Income Taxes [Line Items]
U.S statutory income taxes rate		35.00%
Non-deductible expenses		(6.80%)
Foreign taxes rate differential		15.10%
Change in valuation allowance		(83.40%)
State income taxes		12.80%
Share based compensation		2.00%
Change in unrecognized taxes expense		(0.90%)
Other		(0.90%)
Effective taxes rate		(27.10%)
US Tax Cuts & Jobs Act Impact
Income Taxes [Line Items]
U.S statutory income taxes rate		0.00%
Non-deductible expenses		0.00%
Foreign taxes rate differential		0.00%
Change in valuation allowance		71.50%
State income taxes		5.90%
Share based compensation		(6.50%)
Change in unrecognized taxes expense		0.10%
Other		(71.00%)
Effective taxes rate		0.00%