Subsequent Events	12 Months Ended
Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	NOTE 16. SUBSEQUENT EVENTS On December 6, 2016, our Board of Directors declared a two-for-one stock split of The Navigators Group, Inc. Common stock, to be effected in the form of a stock dividend. Stockholders of record at the close of business on December 30, 2016 received one additional share of Common stock for every share of Common stock held. The additional shares of Common stock were issued on January 20, 2017. All disclosures of shares and per share data have been retroactively adjusted to reflect the stock split for all periods presented. In addition, on February 16, 2017, our Board of Directors declared a cash dividend on The Navigators Group, Inc. Common stock of $0.045 per share, payable on March 24, 2017 to stockholders of record on March 3, 2017. Effective January 1, 2017, we entered into a reinsurance arrangement to cede 100% of the unearned premium as of such date on the North American exposures of our Property business underwritten at Lloyd’s to Vibe Syndicate Management Limited (“Vibe”). All losses occurring after the effective date on this business will be covered by Vibe. Also, effective January 1, 2017, the Parent Company sold its insurance agency operations in Sweden and Denmark to Ryan Specialty Group, LLC (“RSG”). The transaction represents a 100% acquisition of its Sweden and Denmark corporations, NUAL AB and Navigators A/S, respectively. This transaction also included the transfer of the operating lease for the Stockholm office to RSG. We do not expect these transactions to have a material effect on our financial statements. On February 16, 2017, our Company entered into that certain Guarantee, pursuant to which it guaranteed all of the liabilities and obligations of NIIC. The Guarantee would remain effective until all of such liabilities and obligations are discharged, and in the event that our Company does not meets its obligations under the Guarantee, any person who is covered by an insurance policy, certificate of coverage or reinsurance contract issued by NIIC would be a third party beneficiary under the Guarantee. Refer to Note 8, Commitment and Contingencies, in the Notes to Consolidated Financial Statements, for additional information on the Guarantee.

NOTE 16. SUBSEQUENT EVENTS

On December 6, 2016, our Board of Directors declared a two-for-one stock split of The Navigators Group, Inc. Common stock, to be effected in the form of a stock dividend. Stockholders of record at the close of business on December 30, 2016 received one additional share of Common stock for every share of Common stock held. The additional shares of Common stock were issued on January 20, 2017. All disclosures of shares and per share data have been retroactively adjusted to reflect the stock split for all periods presented. In addition, on February 16, 2017, our Board of Directors declared a cash dividend on The Navigators Group, Inc. Common stock of $0.045 per share, payable on March 24, 2017 to stockholders of record on March 3, 2017.

Effective January 1, 2017, we entered into a reinsurance arrangement to cede 100% of the unearned premium as of such date on the North American exposures of our Property business underwritten at Lloyd’s to Vibe Syndicate Management Limited (“Vibe”). All losses occurring after the effective date on this business will be covered by Vibe. Also, effective January 1, 2017, the Parent Company sold its insurance agency operations in Sweden and Denmark to Ryan Specialty Group, LLC (“RSG”). The transaction represents a 100% acquisition of its Sweden and Denmark corporations, NUAL AB and Navigators A/S, respectively. This transaction also included the transfer of the operating lease for the Stockholm office to RSG. We do not expect these transactions to have a material effect on our financial statements.

On February 16, 2017, our Company entered into that certain Guarantee, pursuant to which it guaranteed all of the liabilities and obligations of NIIC. The Guarantee would remain effective until all of such liabilities and obligations are discharged, and in the event that our Company does not meets its obligations under the Guarantee, any person who is covered by an insurance policy, certificate of coverage or reinsurance contract issued by NIIC would be a third party beneficiary under the Guarantee. Refer to Note 8, Commitment and Contingencies, in the Notes to Consolidated Financial Statements, for additional information on the Guarantee.