Leases - Summary of Lease Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Operating lease assets	$ 291,385	$ 0
Finance lease assets	$ 4,560
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsMember
Total lease assets	$ 295,945
Liabilities
Operating lease liabilities	322,776	$ 0
Finance lease liabilities	$ 4,814
Finance Lease, Liability, Statement of Financial Position [Extensible List]	faf:NotesAndContractsPayableMember
Total lease liabilities	$ 327,590