Segment Information (Financial Information By Segment) (Details) $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2015 USD ($)		Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) segment		Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment											5
Segment Reporting Information [Line Items]
Net earned premiums											$ 8,350,997		$ 8,632,142	$ 7,759,796
Net investment income											626,217		656,429	650,296
Net realized gains on investments											31,826		60,783	34,525
Amortization of deferred gain on disposal of businesses											12,988		(1,506)	16,310
Fees and other income											1,303,466		1,033,805	586,730
Total revenues		$ 2,547,834		$ 2,534,156	$ 2,644,894	$ 2,598,610	$ 2,622,692	$ 2,702,488	$ 2,608,101	$ 2,448,372	10,325,494		10,381,653	9,047,657
Policyholder benefits											4,742,535		4,405,333	3,675,532
Amortization of deferred acquisition costs and value of business acquired											1,402,573		1,485,558	1,470,287
Underwriting, general and administrative expenses											3,924,089		3,688,230	3,034,404
Interest expense											55,116		58,395	77,735
Total benefits, losses and expenses											10,124,313		9,637,516	8,257,958
Income before benefit for income taxes		110,214		(32,251)	40,025	83,193	90,346	224,751	193,787	235,253	201,181		744,137	789,699
Provision (benefit) for income taxes											59,626		273,230	300,792
Net income		65,744		$ (7,022)	$ 32,789	$ 50,044	49,755	$ 140,297	$ 143,610	$ 137,245	141,555		470,907	488,907
Segment assets, excluding goodwill							30,721,227						30,721,227	28,930,128
Goodwill		833,512					841,239				833,512		841,239	784,561
Total assets		30,043,128	[1]				31,562,466				30,043,128	[1]	31,562,466	29,714,689
Solutions
Segment Reporting Information [Line Items]
Net earned premiums											3,015,846		3,128,868	2,783,758
Net investment income											376,683		382,640	376,245
Net realized gains on investments											0		0	0
Amortization of deferred gain on disposal of businesses											0		0	0
Fees and other income											785,611		667,852	400,370
Total revenues											4,178,140		4,179,360	3,560,373
Policyholder benefits											919,403		1,027,469	895,504
Amortization of deferred acquisition costs and value of business acquired											1,078,551		1,106,889	1,132,298
Underwriting, general and administrative expenses											1,903,712		1,723,169	1,341,961
Interest expense											0		0	0
Total benefits, losses and expenses											3,901,666		3,857,527	3,369,763
Income before benefit for income taxes											276,474		321,833	190,610
Provision (benefit) for income taxes											79,291		102,885	65,458
Net income											197,183		218,948	125,152
Segment assets, excluding goodwill							14,260,609						14,260,609	13,321,648
Goodwill	[2]	529,093					539,653				529,093		539,653	496,201
Specialty Property
Segment Reporting Information [Line Items]
Net earned premiums											2,044,701		2,506,097	2,380,044
Net investment income											92,859		101,908	98,935
Net realized gains on investments											0		0	0
Amortization of deferred gain on disposal of businesses											0		0	0
Fees and other income											405,545		301,048	133,135
Total revenues											2,543,105		2,909,053	2,612,114
Policyholder benefits											788,549		1,085,339	890,409
Amortization of deferred acquisition costs and value of business acquired											280,492		343,314	309,332
Underwriting, general and administrative expenses											1,010,445		961,972	758,941
Interest expense											0		0	0
Total benefits, losses and expenses											2,079,486		2,390,625	1,958,682
Income before benefit for income taxes											463,619		518,428	653,432
Provision (benefit) for income taxes											155,914		176,671	229,846
Net income											307,705		341,757	423,586
Segment assets, excluding goodwill							4,010,393						4,010,393	3,858,314
Goodwill		304,419					301,586				304,419		301,586	288,360
Health
Segment Reporting Information [Line Items]
Net earned premiums											2,223,696		1,945,452	1,581,407
Net investment income											24,487		35,369	36,664
Net realized gains on investments											0		0	0
Amortization of deferred gain on disposal of businesses											0		0	0
Fees and other income											54,622		40,016	29,132
Total revenues											2,302,805		2,020,837	1,647,203
Policyholder benefits											2,301,241		1,575,633	1,169,075
Amortization of deferred acquisition costs and value of business acquired											10,694		4,570	801
Underwriting, general and administrative expenses											516,726		491,248	434,749
Interest expense											0		0	0
Total benefits, losses and expenses											2,828,661		2,071,451	1,604,625
Income before benefit for income taxes											(525,856)		(50,614)	42,578
Provision (benefit) for income taxes											(157,949)		13,134	36,721
Net income											(367,907)		(63,748)	5,857
Segment assets, excluding goodwill							1,210,615						1,210,615	884,077
Goodwill		0					0				0		0	0
Employee Benefits
Segment Reporting Information [Line Items]
Net earned premiums											1,066,754		1,051,725	1,014,587
Net investment income											110,998		117,192	117,853
Net realized gains on investments											0		0	0
Amortization of deferred gain on disposal of businesses											0		0	0
Fees and other income											25,006		24,204	23,434
Total revenues											1,202,758		1,193,121	1,155,874
Policyholder benefits											730,192		716,892	715,656
Amortization of deferred acquisition costs and value of business acquired											32,836		30,785	27,856
Underwriting, general and administrative expenses											365,921		368,763	360,303
Interest expense											0		0	0
Total benefits, losses and expenses											1,128,949		1,116,440	1,103,815
Income before benefit for income taxes											73,809		76,681	52,059
Provision (benefit) for income taxes											26,487		28,000	17,506
Net income											47,322		48,681	34,553
Segment assets, excluding goodwill							2,242,145						2,242,145	2,298,698
Goodwill		0					0				0		0	0
Corporate & Other
Segment Reporting Information [Line Items]
Net earned premiums											0		0	0
Net investment income											21,190		19,320	20,599
Net realized gains on investments											31,826		60,783	34,525
Amortization of deferred gain on disposal of businesses											12,988		(1,506)	16,310
Fees and other income											32,682		685	659
Total revenues											98,686		79,282	72,093
Policyholder benefits											3,150		0	4,888
Amortization of deferred acquisition costs and value of business acquired											0		0	0
Underwriting, general and administrative expenses											127,285		143,078	138,450
Interest expense											55,116		58,395	77,735
Total benefits, losses and expenses											185,551		201,473	221,073
Income before benefit for income taxes											(86,865)		(122,191)	(148,980)
Provision (benefit) for income taxes											(44,117)		(47,460)	(48,739)
Net income											(42,748)		(74,731)	(100,241)
Segment assets, excluding goodwill							$ 8,997,465						$ 8,997,465	$ 8,567,391
Operating Segments | Solutions
Segment Reporting Information [Line Items]
Total assets	[1]	14,356,484									14,356,484
Operating Segments | Specialty Property
Segment Reporting Information [Line Items]
Total assets	[1]	3,648,738									3,648,738
Operating Segments | Health
Segment Reporting Information [Line Items]
Total assets	[1]	1,437,032									1,437,032
Operating Segments | Employee Benefits
Segment Reporting Information [Line Items]
Total assets	[1]	2,190,808									2,190,808
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Total assets	[1]	$ 8,410,066									$ 8,410,066

[1] As of December 31, 2014, all goodwill on Assurant's balance sheet was held in the Corporate & Other segment. Beginning January 1, 2015, goodwill is included on the respective segment balance sheets.

[2] The accumulated impairment loss relates to an acquisition made in 1999. The entity acquired had businesses that currently are primarily represented by the Assurant Solutions and Assurant Specialty Property segments. Prior to 2006, the Assurant Solutions and Assurant Specialty Property segments were combined and together called Assurant Solutions. Thus, the entire goodwill impairment recognized in 2002 due to the adoption of FAS 142 is included in the tables under the Assurant Solutions segment.