Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Data cost incurred	$ 1,688	$ 1,241
Total capital commitment under certain data licensing agreements	$ 20,275

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

No definition available.

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant