v2.4.0.8
Segments - Net Income (Loss) and Total Assets (Details) (USD $)
 3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Segment
Sep. 30, 2012
Dec. 31, 2012
Segment Reporting Information [Line Items]          
Number of operating segments     3    
Net Income (Loss) [Abstract]          
Net premiums written $ 463,418,000 $ 455,847,000 $ 1,650,426,000 $ 1,458,640,000  
Net premiums earned 508,126,000 448,973,000 1,509,841,000 1,324,585,000  
Other insurance revenue 3,271,000 2,622,000 11,266,000 9,650,000  
Net loss and loss adjustment expenses (341,629,000) (309,146,000) (1,019,871,000) (897,498,000)  
Commission and other acquisition expenses (144,194,000) (120,923,000) (420,096,000) (367,844,000)  
General and administrative expenses (10,369,000) (9,990,000) (33,667,000) (33,859,000)  
Underwriting income 15,205,000 11,536,000 47,473,000 35,034,000  
Reconciliation to net income attributable to Maiden common shareholders          
Net investment income and realized gains on investment 23,730,000 23,960,000 69,684,000 60,908,000  
Amortization of intangible assets (945,000) (1,090,000) (2,835,000) (3,271,000)  
Foreign exchange and other gains (losses) (23,000) 1,213,000 2,573,000 1,318,000  
Interest and amortization expenses (9,571,000) (9,569,000) (28,711,000) (26,815,000)  
Other general and administrative expenses (2,882,000) (3,588,000) (10,496,000) (8,758,000)  
Income tax expense (481,000) (528,000) (1,217,000) (1,498,000)  
Net income attributable to noncontrolling interest (36,000) (15,000) (95,000) (81,000)  
Dividends on preference shares (3,093,000) 0 (9,281,000) 0  
Net income attributable to Maiden common shareholders 21,904,000 21,919,000 67,095,000 56,837,000  
Net loss and loss adjustment expense ratio 66.80% [1] 68.50% [1] 67.00% [1] 67.30% [1]  
Commission and other acquisition expense ratio 28.20% [2] 26.80% [2] 27.60% [2] 27.60% [2]  
General and administrative expense ratio 2.60% [3] 2.90% [3] 3.00% [3] 3.10% [3]  
Combined ratio 97.60% [4] 98.20% [4] 97.60% [4] 98.00% [4]  
Assets [Abstract]          
Reinsurance balance receivable, net 554,680,000   554,680,000   522,614,000
Funds withheld 45,492,000   45,492,000   42,712,000
Prepaid reinsurance premiums 49,515,000   49,515,000   38,725,000
Reinsurance recoverable on unpaid losses 97,334,000   97,334,000   110,858,000
Deferred commissions and other acquisition expenses 310,726,000   310,726,000   270,669,000
Loan to related party 167,975,000   167,975,000   167,975,000
Goodwill and intangible assets, net 91,558,000   91,558,000   94,393,000
Restricted cash and cash equivalents and investments 2,304,669,000   2,304,669,000   2,167,318,000
Other assets 8,164,000   8,164,000   5,864,000
Total Assets - Operating Segments 3,630,113,000   3,630,113,000   3,421,128,000
Corporate assets 819,559,000   819,559,000   717,035,000
Total assets 4,449,672,000   4,449,672,000   4,138,163,000
Diversified Reinsurance Segment [Member]
          
Net Income (Loss) [Abstract]          
Net premiums written 185,620,000 193,943,000 588,164,000 626,220,000  
Net premiums earned 198,966,000 200,020,000 573,551,000 603,613,000  
Other insurance revenue 3,271,000 2,622,000 11,266,000 9,650,000  
Net loss and loss adjustment expenses (137,080,000) (141,625,000) (398,680,000) (412,437,000)  
Commission and other acquisition expenses (51,657,000) (47,801,000) (140,877,000) (159,895,000)  
General and administrative expenses (9,688,000) (9,256,000) (31,639,000) (31,849,000)  
Underwriting income 3,812,000 3,960,000 13,621,000 9,082,000  
Reconciliation to net income attributable to Maiden common shareholders          
Net loss and loss adjustment expense ratio 67.80% [1] 69.90% [1] 68.20% [1] 67.30% [1]  
Commission and other acquisition expense ratio 25.50% [2] 23.60% [2] 24.10% [2] 26.10% [2]  
General and administrative expense ratio 4.80% [3] 4.50% [3] 5.40% [3] 5.10% [3]  
Combined ratio 98.10% [4] 98.00% [4] 97.70% [4] 98.50% [4]  
Assets [Abstract]          
Reinsurance balance receivable, net 283,368,000   283,368,000   260,161,000
Funds withheld 45,492,000   45,492,000   42,712,000
Prepaid reinsurance premiums 49,515,000   49,515,000   38,725,000
Reinsurance recoverable on unpaid losses 97,334,000   97,334,000   110,858,000
Deferred commissions and other acquisition expenses 88,060,000   88,060,000   83,287,000
Loan to related party 0   0   0
Goodwill and intangible assets, net 91,558,000   91,558,000   94,393,000
Restricted cash and cash equivalents and investments 1,107,671,000   1,107,671,000   1,219,454,000
Other assets 8,164,000   8,164,000   5,864,000
Total Assets - Operating Segments 1,771,162,000   1,771,162,000   1,855,454,000
Corporate assets 0   0   0
Total assets 1,771,162,000   1,771,162,000   1,855,454,000
AmTrust Quota Share Reinsurance Segment [Member]
          
Net Income (Loss) [Abstract]          
Net premiums written 259,633,000 186,258,000 895,029,000 607,902,000  
Net premiums earned 243,408,000 177,293,000 725,100,000 512,988,000  
Other insurance revenue 0 0 0 0  
Net loss and loss adjustment expenses (160,212,000) (120,942,000) (478,782,000) (350,553,000)  
Commission and other acquisition expenses (71,869,000) (50,525,000) (213,199,000) (142,284,000)  
General and administrative expenses (504,000) (535,000) (1,498,000) (1,444,000)  
Underwriting income 10,823,000 5,291,000 31,621,000 18,707,000  
Reconciliation to net income attributable to Maiden common shareholders          
Net loss and loss adjustment expense ratio 65.80% [1] 68.20% [1] 66.00% [1] 68.30% [1]  
Commission and other acquisition expense ratio 29.50% [2] 28.50% [2] 29.40% [2] 27.70% [2]  
General and administrative expense ratio 0.30% [3] 0.30% [3] 0.20% [3] 0.40% [3]  
Combined ratio 95.60% [4] 97.00% [4] 95.60% [4] 96.40% [4]  
Assets [Abstract]          
Reinsurance balance receivable, net 210,447,000   210,447,000   170,983,000
Funds withheld 0   0   0
Prepaid reinsurance premiums 0   0   0
Reinsurance recoverable on unpaid losses 0   0   0
Deferred commissions and other acquisition expenses 202,691,000   202,691,000   153,530,000
Loan to related party 167,975,000   167,975,000   167,975,000
Goodwill and intangible assets, net 0   0   0
Restricted cash and cash equivalents and investments 1,095,601,000   1,095,601,000   857,013,000
Other assets 0   0   0
Total Assets - Operating Segments 1,676,714,000   1,676,714,000   1,349,501,000
Corporate assets 0   0   0
Total assets 1,676,714,000   1,676,714,000   1,349,501,000
NGHC Quota Share Segment [Member]
          
Net Income (Loss) [Abstract]          
Net premiums written 18,165,000 75,646,000 167,233,000 224,518,000  
Net premiums earned 65,752,000 71,660,000 211,190,000 207,984,000  
Other insurance revenue 0 0 0 0  
Net loss and loss adjustment expenses (44,337,000) (46,579,000) (142,409,000) (134,508,000)  
Commission and other acquisition expenses (20,668,000) (22,597,000) (66,020,000) (65,665,000)  
General and administrative expenses (177,000) (199,000) (530,000) (566,000)  
Underwriting income 570,000 2,285,000 2,231,000 7,245,000  
Reconciliation to net income attributable to Maiden common shareholders          
Net loss and loss adjustment expense ratio 67.40% [1] 65.00% [1] 67.40% [1] 64.70% [1]  
Commission and other acquisition expense ratio 31.40% [2] 31.50% [2] 31.30% [2] 31.60% [2]  
General and administrative expense ratio 0.30% [3] 0.30% [3] 0.20% [3] 0.20% [3]  
Combined ratio 99.10% [4] 96.80% [4] 98.90% [4] 96.50% [4]  
Assets [Abstract]          
Reinsurance balance receivable, net 60,865,000   60,865,000   91,470,000
Funds withheld 0   0   0
Prepaid reinsurance premiums 0   0   0
Reinsurance recoverable on unpaid losses 0   0   0
Deferred commissions and other acquisition expenses 19,975,000   19,975,000   33,852,000
Loan to related party 0   0   0
Goodwill and intangible assets, net 0   0   0
Restricted cash and cash equivalents and investments 101,397,000   101,397,000   90,851,000
Other assets 0   0   0
Total Assets - Operating Segments 182,237,000   182,237,000   216,173,000
Corporate assets 0   0   0
Total assets $ 182,237,000   $ 182,237,000   $ 216,173,000
[1] Calculated by dividing net loss and loss adjustment expenses by the sum of net premiums earned and other insurance revenue.
[2] Calculated by dividing commission and other acquisition expenses by the sum of net premiums earned and other insurance revenue.
[3] Calculated by dividing general and administrative expenses by the sum of net premiums earned and other insurance revenue.
[4] Calculated by adding together net loss and loss adjustment expense ratio, commission and other acquisition expense ratio and general and administrative expense ratio.