Organization and Business (Details)	2 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Jul. 31, 2015 USD ($)	Jun. 09, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Agent Carrier	Sep. 30, 2014 USD ($)
Business Organization [Line Item]
Number of independent agents | Agent						3,900
Number of agents that actively sell and service the entity's products | Agent						2,500
Ratio of homeowners' premiums underwritten to total premiums underwritten				91.60%	90.50%	92.30%	91.20%
Ratio of commercial general liability premiums underwritten to total premiums underwritten				2.60%	3.40%	3.00%	3.40%
Ratio of federal flood premiums underwritten to total premiums underwritten				3.80%	2.50%	2.90%	2.20%
Ratio of automobile insurance premiums underwritten to total premiums underwritten				2.00%	3.60%	1.80%	3.20%
Portion of homeowners' gross premium written produced under "ISA"				$ 28,600,000	$ 19,000,000	$ 75,700,000	$ 49,400,000
Percentage of homeowners' gross premium written produced under "ISA"				24.10%	22.80%	22.20%	19.30%
Homeowners' gross premiums written				$ 118,900,000	$ 83,300,000	$ 340,200,000	$ 255,900,000
Portion of increased homeowners' gross premium written produced under "ISA"				$ 9,600,000		$ 26,300,000
Percentage of increased homeowners' gross premium written produced under "ISA"				27.00%		31.20%
Increased homeowners' gross premiums written				$ 35,600,000		$ 84,300,000
Original percentage commission fee from its affiliate				4.00%
Minimum [Member]
Business Organization [Line Item]
Number of carriers the entity provides insurance through | Carrier						100
Federated National Underwriters, Inc. [Member] | Minimum [Member]
Business Organization [Line Item]
Fees earned per policy				$ 25
Federated National Underwriters, Inc. [Member] | Maximum [Member]
Business Organization [Line Item]
Fees earned per policy				55
Florida [Member]
Product Information [Line Items]
Weekly homeowners' gross premiums written	$ 3,300,000	$ 4,900,000	$ 3,300,000
Period for average weekly new premium written after discontinuing use of underwriting analytics		49 days
Increase in average weekly new premium written		48.00%
Monarch Delaware Holdings LLC [Member]
Business Organization [Line Item]
Capital contribution for voting interests	$ 14,000,000			$ 14,000,000		$ 14,000,000
Ownership interest in Monarch Parent's equity	42.40%			42.40%		42.40%
Voting interest held in Monarch Parent's equity	50.00%			50.00%		50.00%
Monarch Delaware Holdings LLC [Member] | C.A. Bancorp Inc. [Member]
Business Organization [Line Item]
Capital contribution for voting interests	$ 14,000,000			$ 14,000,000		$ 14,000,000
Ownership interest in Monarch Parent's equity	42.40%			42.40%		42.40%
Voting interest held in Monarch Parent's equity	50.00%			50.00%		50.00%
Monarch Delaware Holdings LLC [Member] | Transatlantic Reinsurance Company [Member]
Business Organization [Line Item]
Capital contribution for voting interests	$ 5,000,000			$ 5,000,000		$ 5,000,000
Ownership interest in Monarch Parent's equity	15.20%			15.20%		15.20%
Monarch Delaware Holdings LLC [Member] | Transatlantic Reinsurance Company [Member] | Senior Debt [Member]
Business Organization [Line Item]
Long-term debt	$ 5,000,000			$ 5,000,000		$ 5,000,000
Maturity period of debt						6 years
Interest rate percentage	6.00%			6.00%		6.00%
Monarch Delaware Holdings LLC [Member] | Federated National Underwriters, Inc. [Member]
Business Organization [Line Item]
Percentage of written annual premium payable to agents for managing general agent services	4.00%			4.00%		4.00%
Percentage of earned annual premium payable for claims administration services	3.60%			3.60%		3.60%
Administrative fee per-policy underwritten	$ 25			$ 25		$ 25
Fire [Member] | Florida [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Fire [Member] | Alabama [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Licensed, but no current operations
Allied Lines [Member] | Florida [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Allied Lines [Member] | Alabama [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Licensed, but no current operations
Private Passenger Automobile [Member] | Florida [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Private Passenger Automobile [Member] | Alabama [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Licensed, but no current operations
Private Passenger Automobile [Member] | Georgia [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Private Passenger Automobile [Member] | Texas [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Homeowners' Multiperil [Member] | Florida [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Homeowners' Multiperil [Member] | Alabama [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Homeowners' Multiperil [Member] | Louisiana [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Homeowners' Multiperil [Member] | South Carolina [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for less than one year
Homeowners' Multiperil [Member] | Texas [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for less than one year
Commercial General Liability [Member] | Florida [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Ongoing operations for more than one year
Commercial General Liability [Member] | Alabama [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Working with state to discontinue line of authority
Commercial General Liability [Member] | Georgia [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Working with state to discontinue line of authority
Commercial General Liability [Member] | Louisiana [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Working with state to discontinue line of authority
Commercial General Liability [Member] | Texas [Member]
Operations by State and Line of Business [Abstract]
Status of operations						Working with state to discontinue line of authority