Summary of Significant Accounting Policies (Details 4)	12 Months Ended
Dec. 31, 2016 USD ($) payment	Dec. 31, 2015 USD ($)
Reserve for Losses and Loss Adjustment Expenses
Number of consecutive missed loan payments by borrower for classification of insured loan as in default \| payment	2
Premium Deficiency Reserve
Premium deficiency reserve \| $	$ 0	$ 0

Represents the amount of reserve for the excess of the net present value of expected future losses and expenses for a particular group of policies over the net present value of expected future premium, anticipated investment income and existing reserves for that specified group of policies.

No definition available.

Name:	esnt_PremiumDeficiencyReserve
Namespace Prefix:	esnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant