Income Taxes (Details 4) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits	$ 0	$ 0
Liability for uncertain tax positions	0	$ 0
Essent Irish Intermediate | Essent Holdings
Operating Loss Carryforwards [Line Items]
Withholding taxes accrued with respect to un-remitted earnings	0
Subsidiaries | U.S.
Operating Loss Carryforwards [Line Items]
Taxes provided on un-remitted earnings	0
Cumulative amount of earnings that would be subject to withholding tax, if distributed outside of the U.S.	$ 550,000,000
United States Ireland Tax Treaty Benefits Availed | Essent Irish Intermediate | Essent Holdings
Operating Loss Carryforwards [Line Items]
Withholding tax rate on dividends paid (as a percent)	5.00%
United States Ireland Tax Treaty Benefits Availed | Subsidiaries | U.S.
Operating Loss Carryforwards [Line Items]
Associated withholding tax liability on cumulative amount of earnings that would be subject to withholding tax, if distributed outside of the U.S.	$ 28,000,000
Absent Benefits Of United States Ireland Tax Treaty | Essent Irish Intermediate | Essent Holdings
Operating Loss Carryforwards [Line Items]
Withholding tax rate on dividends paid (as a percent)	30.00%