Assurant (AIZ) 10-Q 9 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Aug. 03, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	ASSURANT INC
Entity Central Index Key	1,267,238
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Trading Symbol	AIZ
Entity Common Stock, Shares Outstanding		62,839,361

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Jun. 30, 2018	Dec. 31, 2017
Investments:
Fixed maturity securities available for sale, at fair value (amortized cost - $10,777.0 in 2018 and $8,756.5 in 2017)		$ 11,297.5	$ 9,662.6
Equity securities, at fair value (cost - $349.6 in 2018 and $316.3 in 2017)		385.8
Equity securities, at fair value (cost - $349.6 in 2018 and $316.3 in 2017)			368
Commercial mortgage loans on real estate, at amortized cost		720.1	670.2
Short-term investments		343.6	284.1
Other investments		642.2	568.6
Total investments		13,389.2	11,553.5
Cash and cash equivalents		1,253.7	996.8
Premiums and accounts receivable, net		1,512.7	1,237.3
Reinsurance recoverables		10,978.3	9,790.2
Accrued investment income		136.1	105.4
Deferred acquisition costs		3,882.7	3,484.5
Property and equipment, at cost less accumulated depreciation		370.6	347.6
Tax receivable		54.3	126.3
Goodwill		2,369.2	917.7
Value of business acquired		3,962.5	24.4
Other intangible assets, net		664.8	288.6
Other assets		623.7	387.1
Assets held in separate accounts		1,858.3	1,837.1
Assets of consolidated investment entities	[1]	1,305.2	746.5
Total assets		42,361.3	31,843
Liabilities
Future policy benefits and expenses		10,386	10,397.4
Unearned premiums		14,505	7,038.6
Claims and benefits payable		3,503.1	3,782.2
Commissions payable		308.1	365.1
Reinsurance balances payable		324.1	145.3
Funds held under reinsurance		347.1	179.8
Deferred gains on disposal of businesses		94.7	128.1
Accounts payable and other liabilities		2,610.7	2,046.3
Debt		2,004.8	1,068.2
Liabilities related to separate accounts		1,858.3	1,837.1
Liabilities of consolidated investment entities	[1]	1,086.5	573.4
Total liabilities		37,028.4	27,561.5
Commitments and contingencies (Note 18)
Stockholders’ equity
6.50% Series D mandatory convertible preferred stock, $1.00 par value, 2,875,000 shares authorized, 2,875,000 issued and outstanding at June 30, 2018		2.9	0
Common stock, par value $0.01 per share, 800,000,000 shares authorized, 161,069,104 and 150,392,604 shares issued and 63,094,312 and 52,417,812 shares outstanding at June 30, 2018 and December 31, 2017, respectively		1.6	1.5
Additional paid-in capital		4,459.7	3,197.9
Retained earnings		5,846.3	5,697.3
Accumulated other comprehensive (loss) income		(137.9)	234
Treasury stock, at cost; 97,974,792 shares at June 30, 2018 and December 31, 2017		(4,860.1)	(4,860.1)
Total Assurant, Inc. stockholders’ equity		5,312.5	4,270.6
Non-controlling interest		20.4	10.9
Total equity		5,332.9	4,281.5
Total liabilities and equity		$ 42,361.3	$ 31,843
[1]	The following table presents information on assets and liabilities related to consolidated investment entities as of June 30, 2018 and December 31, 2017

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Jun. 30, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents		$ 35	$ 69.8
Investments, at fair value		1,200.7	655
Other receivables		69.5	21.7
Total assets	[1]	1,305.2	746.5
Liabilities
Collateralized loan obligation notes, at fair value		941.2	450.7
Other liabilities		145.3	122.7
Total liabilities	[1]	1,086.5	573.4
Fixed maturity securities available for sale, amortized cost		10,777	8,756.5
Equity securities, cost		$ 349.6
Equity securities available for sale, cost			$ 316.3
Preferred stock, par value (in dollars per share)		$ 1
Preferred stock, shares authorized (in shares)		2,875,000
Preferred stock, shares issued (in shares)		2,875,000
Preferred stock, shares outstanding (in shares)		2,875,000
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized (in shares)		800,000,000	800,000,000
Common Stock, Shares, Issued		161,069,104	150,392,604
Common stock, shares outstanding (in shares)		63,094,312	52,417,812
Treasury stock, at cost (in shares)		97,974,792	97,974,792
[1]	The following table presents information on assets and liabilities related to consolidated investment entities as of June 30, 2018 and December 31, 2017

Consolidated Statements of Oper

Consolidated Statements of Operations (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Net earned premiums	$ 1,338.3	$ 1,115.3	$ 2,463.2	$ 2,165.6
Fees and other income	354.2	326.9	718.7	667.1
Net investment income	135.6	121.7	265.8	242.3
Net realized (losses) gains on investments, excluding other-than-temporary impairment losses		13.3		17.1
Net realized (losses) gains on investments, excluding other-than-temporary impairment losses	(11.4)		(10.9)
Other-than-temporary impairment losses recognized in earnings	0	(0.1)	0	(0.5)
Amortization of deferred gains on disposal of businesses	15	23.4	33.5	60.4
Total revenues	1,831.7	1,600.5	3,470.3	3,152
Benefits, losses and expenses
Policyholder benefits	490.6	416.4	905.2	774.4
Amortization of deferred acquisition costs and value of business acquired	463.2	346.7	809.6	661.2
Underwriting, general and administrative expenses	773.6	646.3	1,493.2	1,297.6
Interest expense	26	12.4	47.5	25
Total benefits, losses and expenses	1,753.4	1,421.8	3,255.5	2,758.2
Income before provision for income taxes	78.3	178.7	214.8	393.8
Provision for income taxes	11.3	58.5	41.8	129.8
Net income	67	120.2	173	264
Less: Preferred stock dividends	(4.8)	0	(4.8)	0
Net income attributable to common stockholders	$ 62.2	$ 120.2	$ 168.2	$ 264
Earnings Per Share
Basic (in dollars per share)	$ 1.09	$ 2.18	$ 3.05	$ 4.74
Diluted (in dollars per share)	1.09	2.16	3.02	4.71
Dividends per share of common stock (in dollars per share)	0.56	0.53	1.12	1.06
Dividends per share of preferred stock (in dollars per share)	$ 1.68	$ 0	$ 1.68	$ 0
Share Data
Weighted average shares outstanding used in basic per share calculations (in shares)	57,060,313	55,230,367	55,125,584	55,713,172
Plus: Dilutive securities (in shares)	204,095	279,531	2,147,844	361,980
Weighted average shares used in diluted earnings per share calculations (in shares)	57,264,408	55,509,898	57,273,428	56,075,152

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 67	$ 120.2	$ 173	$ 264
Other comprehensive (loss) income:
Change in unrealized gains on securities, net of taxes of $28.2, $(40.7), $76.0 and $(57.7), respectively	(105.9)	73.9	(281.1)	106.3
Change in unrealized gains on derivative transactions, net of taxes of $0.2 and $(5.4) for the three and six months ended June 30, 2018, respectively	(0.2)	0	20.9	0
Change in other-than-temporary impairment losses, net of taxes of $0.4, $0.8, $1.3 and $1.0, respectively	(1.4)	(1.5)	(4.9)	(1.8)
Change in foreign currency translation, net of taxes of $1.0, $(0.9), $1.5 and $(1.3), respectively	(83.1)	15.7	(73.9)	37.5
Amortization of pension and postretirement unrecognized net periodic benefit cost, net of taxes of $(0.3), $(0.3), $(0.3) and $(0.2), respectively	1	0.5	1	0.3
Total other comprehensive (loss) income	(189.6)	88.6	(338)	142.3
Total comprehensive (loss) income	$ (122.6)	$ 208.8	$ (165)	$ 406.3

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net change in unrealized gains on securities, taxes	$ 28.2	$ (40.7)	$ 76	$ (57.7)
Net change in unrealized gains on derivative transactions, taxes	0.2	0	(5.4)	0
Net change in other-than-temporary impairment gains, taxes	0.4	0.8	1.3	1
Net change in foreign currency translation, taxes	1	(0.9)	1.5	(1.3)
Net change in pension plan curtailment and amortization of pension and postretirement unrecognized net periodic benefit cost, taxes	$ (0.3)	$ (0.3)	$ (0.3)	$ (0.2)

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (unaudited) - 6 months ended Jun. 30, 2018 - USD ($) $ in Millions		Total	Common Stock	Preferred Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock	Non-controlling Interest	Preferred Stock	Preferred StockPreferred Stock	Preferred StockAdditional Paid-in Capital
Beginning balance at Dec. 31, 2017		$ 4,281.5	$ 1.5	$ 0	$ 3,197.9	$ 5,697.3	$ 234	$ (4,860.1)	$ 10.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan exercises		(8.8)			(8.8)
Stock plan compensation		21.7		0	21.7
Common stock dividends		(60.6)				(60.6)
Net income		173				173
Issuance of preferred stock		975.5	0.1		975.4					$ 276.4	$ 2.9	$ 273.5
Issuance of common stock		975.5	0.1		975.4					$ 276.4	$ 2.9	$ 273.5
Preferred stock dividends		(4.8)				(4.8)
Change in equity of non-controlling interest		9.5							9.5
Other comprehensive income		(338)					(338)
Ending balance at Jun. 30, 2018		5,332.9	$ 1.6	$ 2.9	$ 4,459.7	5,846.3	(137.9)	$ (4,860.1)	$ 20.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principles, net of taxes | Accounting Standards Update 2016-01 and 2014-09	[1]	$ 7.5				$ 41.4	$ (33.9)
[1]	Amounts relate to 1) the requirement to recognize the fair value changes of equity securities directly within income (resulting in a reclassification of unrealized gains as of December 31, 2017 between accumulated other comprehensive income ("AOCI") and retained earnings) and 2) the impact of adoption of the new revenue recognition standard for revenues from service contracts and sales of products. See Note 3 for additional information.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Statement of Cash Flows [Abstract]
Net cash provided by (used in) operating activities	[1]	$ 172.3	$ (0.3)
Sales of:
Fixed maturity securities available for sale		1,465.8	1,653.4
Equity securities		57.2	43.8
Other invested assets		35.6	35.5
Maturities, calls, prepayments, and scheduled redemption of:
Fixed maturity securities available for sale		377.1	448.2
Commercial mortgage loans on real estate		78.3	69
Purchases of:
Fixed maturity securities available for sale		(1,646.8)	(1,880.8)
Equity securities available for sale		(39.4)	(14.7)
Commercial mortgage loans on real estate		(131.6)	(69)
Other invested assets		(19.7)	(157.2)
Property and equipment and other		(38.1)	(31.1)
Subsidiaries, net of cash transferred	[2]	(1,213.5)	(127.4)
Consolidated investment entities
Purchases of investments	[3]	(828.3)	0
Sale of investments	[3]	294.8	0
Change in short-term investments		94.9	34.8
Other		(1.1)	(0.8)
Net cash (used in) provided by investing activities		(1,514.8)	3.7
Financing activities
Issuance of mandatory convertible preferred stock, net of issuance costs	[4]	276.4	0
Issuance of debt, net of issuance costs	[4]	1,286.1	69
Repayment of debt	[4]	(350)	0
Issuance of collateralized loan obligation notes		404.9	0
Issuance of debt for consolidated investment entities	[3]	385.4	0
Repayment of debt for consolidated investment entities		(296.3)	0
Acquisition of common stock		(6.9)	(218.6)
Common stock dividends paid		(60.6)	(60)
Preferred stock dividends paid		(4.8)	0
Non-controlling interest		7.7	0
Withholding on stock based compensation		6.1	17.3
Other		(3.5)	0
Net cash provided by (used in) financing activities		1,644.5	(192.3)
Effect of exchange rate changes on cash and cash equivalents		(22.8)	5.1
Cash included in business classified as held for sale		(22.3)	0
Change in cash and cash equivalents		256.9	(183.8)
Cash and cash equivalents at beginning of period		996.8	1,032
Cash and cash equivalents at end of period		$ 1,253.7	$ 848.2
[1]	The increase in net cash from operating activities for the six months ended June 30, 2018 as compared to the comparable 2017 period was primarily due to the absence of an $85.0 million payment made in 2017 related to the lender-placed market conduct examination settlement agreements. Also contributing was an increase of sales in our Connected Living business, lower inventory purchases in our mobile business and $26.7 million increase in cash from the settlement of a series of derivative transactions that we entered into in 2017 to hedge interest rate risk related to the anticipated borrowings to be used for the TWG acquisition (all in 2018). These are partially offset by a $41.5 million
[2]	Amounts for the six months ended June 30, 2018 primarily consist of $1.49 billion of cash used to fund a portion of the total purchase of the TWG acquisition, inclusive of the $595.9 million repayment of pre-existing TWG debt at the Acquisition Date (such debt was not legally assumed by Assurant), net of $277.3 million in TWG cash acquired. The remaining consideration for the TWG acquisition was funded by the issuance of 10,399,862
[3]	Relates to cash flows from our variable interest entities. Refer to Note 8 - Variable Interest Entities, for further information.
[4]	Refer to Note 12 - Debt, for additional information.

Consolidated Statements of Cas9

Consolidated Statements of Cash Flows (unaudited) (Parenthetical) - USD ($) $ in Millions	May 31, 2018	Jun. 30, 2018	Jun. 30, 2017
Payments of examination, compliance, and monitoring costs			$ 85
Payments of accrued indemnification liability		$ 41.5
Derivative
Derivative qualified for hedge accounting gain (loss)		$ 26.7
TWG Holdings Limited
Payments to Acquire Businesses, Including Repayment of Pre-Existing Debt	$ 1,490
Repayment of pre-existing TWG debt	595.9
Business combinations, cash acquired	$ 277.3
Common stock shares issued to TWG equityholders	10,399,862

Nature of Operations

Nature of Operations	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations Assurant, Inc. (the “Company”) is a holding company whose subsidiaries globally provide risk management solutions in the housing and lifestyle markets, protecting where consumers live and the goods they buy. The Company is traded on the New York Stock Exchange under the symbol "AIZ".

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. Accordingly, these statements do not include all of the information and notes required by GAAP for complete financial statements. The consolidated financial statements include the results of TWG from June 1, 2018. The interim financial data as of June 30, 2018 and for the three and six months ended June 30, 2018 and 2017 is unaudited; in the opinion of management, the interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods. The unaudited interim consolidated financial statements include the accounts of the Company and all of its wholly owned subsidiaries. All inter-company transactions and balances are eliminated in consolidation.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted Revenue recognition from contracts with customers: On January 1, 2018, the Company adopted the new guidance related to revenue recognition from contracts with customers. The new guidance was adopted using the modified retrospective approach, whereby the cumulative effect of adoption to retained earnings was recognized as of January 1, 2018 and the comparative information was not restated and continues to be reported under the accounting standards in effect for those periods. The guidance affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards. Insurance and similar contracts issued by insurance entities are specifically excluded from the scope of the amended revenue recognition guidance. As such, this standard only applies to the Company’s service contracts and sales of products, including those related to providing administrative services, mobile device related services, mortgage property risk management services and similar fee for service arrangements. Revenues from these contracts correspond to approximately 20% of the Company’s total 2017 revenues. The standard utilizes a five-step approach that emphasizes the recognition of revenue when the performance obligations are met by the Company in order to reflect the transfer of promised goods or services to customers in an amount that reflects the consideration the Company expects to receive. As of the adoption date, accounts payable and other liabilities decreased by $10.0 million , other assets decreased by $0.3 million , retained earnings increased by $7.5 million , and deferred taxes increased by $2.2 million due to a change in the revenue recognition associated with certain mobile upgrade programs. The change reflects the recognition of upgrade revenue in proportion to the pattern of rights expected to be exercised as opposed to recognition when the event (upgrade or end of term) occurs. The comparable mobile upgrade programs impacted by this change were immaterial in prior periods. Upon adoption of the new revenue recognition guidance, the Company’s revenues for service contracts and sales of products are subject to additional disclosure requirements, such as those related to providing disaggregated revenue disclosure, changes in contract balances, enhanced description of performance obligations, basis of determining costs and related significant judgments used in determining appropriate revenue recognition procedures. Refer to Note 6 for the Contract Revenues note. Financial instruments measurement and classification: On January 1, 2018, the Company adopted the amended guidance on the measurement and classification of financial instruments whereby all common and preferred stocks are measured at fair value through the income statement. Upon adoption, the Company recorded a cumulative effect adjustment to increase retained earnings by $33.9 million , which represents a reclassification from AOCI of the unrealized gains on common and preferred stock as of the date of adoption. The Company's other-than-temporary impairment policies have been updated to reflect that the change in value for preferred and common stocks are now reported in net income. For certain private equity investments recorded in Other investments, the Company elected the measurement alternative to record these investments at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer. The measurement alternative has been applied on a prospective basis. Income tax consequences for intra-entity transfers of assets: On January 1, 2018, the Company adopted the amended guidance on tax accounting for intra-entity transfers of assets. The amended guidance requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs as opposed to when it has been sold to an outside party. Also, the amended guidance eliminates the exception for an intra-entity transfer of an asset other than inventory. The adoption of this amended guidance did not have an impact on the Company’s financial position and results of operations. Statement of cash flows presentation and classification: On January 1, 2018, the Company adopted the amended guidance on presentation and classification in the statement of cash flows. The amended guidance addresses certain specific cash flow issues including debt prepayment and debt extinguishment costs; settlement of zero-coupon or insignificant coupon debt instruments; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (including bank-owned life insurance policies); distributions received from equity method investees; beneficial interests in securitization transactions; and guidance related to the identification of the primary source for separately identifiable cash flows. The adoption of this amended guidance did not have an impact on the Company’s financial position and results of operations. Accounting for hedging activities : On January 1, 2018, the Company adopted the amended guidance related to hedge effectiveness testing requirements, income statement presentation and disclosure and hedge accounting qualification criteria. The amended guidance requires that realized gains and losses on forecasted transactions are recorded in the financial statement line item to which the underlying forecasted transactions relates; simplifies the ongoing effectiveness testing; and reduces the complexity of hedge accounting requirements for new derivative contracts. The adoption of this amended guidance did not have a material impact on the Company's financial position and results of operations. Not Yet Adopted Classification of certain tax effects from accumulated other comprehensive income: In February 2018, the Financial Accounting Standards Board ("FASB") issued amended guidance on reclassifying the stranded tax effects from the Tax Cuts and Jobs Act of 2017 from accumulated other comprehensive income to retained earnings. The amended guidance is effective in fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Therefore, the Company is required to adopt the guidance on January 1, 2019. Early adoption is permitted, including adoption in any interim period for reporting periods in which financial statements have not yet been issued. The amendments in this guidance should be applied either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act is recognized. The adoption of this amended guidance will not have a material impact on the Company's financial position and results of operations. Reporting credit losses of assets held at amortized cost : In June 2016, the FASB issued amended guidance on reporting credit losses for assets held at amortized cost and available for sale debt securities. For assets held at amortized cost, the amended guidance eliminates the probable recognition threshold and instead requires an entity to reflect the current estimate of all expected credit losses. For available for sale debt securities, credit losses will be measured in a manner similar to current accounting requirements; however, the amended guidance requires that credit losses be presented as an allowance rather than as a permanent impairment. The amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. The amended guidance is effective in fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Therefore, the Company is required to adopt the guidance on January 1, 2020. Early adoption is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the requirements of this amended guidance and the potential impact on the Company’s financial position and results of operations. Lease accounting

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Acquisitions	Acquisitions TWG Acquisition On May 31, 2018 (the “Acquisition Date”), the Company completed the acquisition of TWG Holdings Limited (“TWG Holdings”) and its subsidiaries for a total enterprise value of $2.47 billion . This reflects $894.9 million in cash, the repayment of TWG’s $595.9 million pre-existing debt and $975.5 million in newly-issued Assurant, Inc. common stock. As a result, the equityholders of TWG Holdings, including TPG Capital, received a total of 10,399,862 shares of Assurant common stock, which represented 16.5% of the Company's outstanding shares of common stock as of June 30, 2018. TWG specializes in the underwriting, administration and marketing of service contracts on a wide variety of consumer goods, including automobiles, consumer electronics and major home appliances. The acquisition will enhance the Company's position as a leading lifestyle provider, particularly within the Global Automotive business, with significant operating synergies expected and a deepened global footprint. The Company financed the cash consideration and repayment of TWG's pre-existing debt through a combination of available cash and external financing. Refer to Notes 12 and 15 for more information on the issuances of debt and mandatory convertible preferred stock, respectively, related to the financing of the acquisition. Acquisition Consideration The table below details the purchase consideration: Calculation of acquisition consideration Common stock shares issued to TWG equityholders 10,399,862 Volume weighted average common share price of Assurant, Inc. on May 31, 2018 $ 93.80 Share issuance consideration $ 975.5 Aggregate cash consideration 894.9 Repayment of pre-existing TWG debt 595.9 Total acquisition consideration $ 2,466.3 Fair Value of Net Assets Acquired and Liabilities Assumed The fair values listed below are preliminary estimates and are subject to adjustment, including assessment of the Value of business acquired ("VOBA") and Other intangible assets, as well as certain components of deferred tax liabilities included within Accounts payable and other liabilities. If necessary, the Company will recognize measurement-period adjustments during the period in which the Company determines the amounts, including the effect on earnings of any amounts that would have been recorded in previous periods if such adjustments were known as of the Acquisition Date. Preliminary estimate of assets acquired and (liabilities) assumed Fixed maturity securities available for sale $ 2,359.3 Equity securities 49.4 Short-term investments 174.5 Other investments 104.2 Cash and cash equivalents 277.3 Premiums and accounts receivable, net 275.2 Reinsurance recoverables 1,917.5 Accrued investment income 31.6 Property and equipment 15.4 Value of business acquired 3,995.7 Other intangible assets 461.4 Other assets 195.5 Unearned premiums and contract fees (7,250.7 ) Claims and benefits payable (423.5 ) Reinsurance balances payable (186.1 ) Funds held under reinsurance (200.8 ) Accounts payable and other liabilities (791.6 ) Non-controlling interest (1.8 ) Total identifiable net assets acquired 1,002.5 Goodwill 1,463.8 Total acquisition consideration $ 2,466.3 The Company recognized Goodwill of $1.46 billion , mainly attributable to expected growth and profitability, none of which is expected to be deductible for income tax purposes. The Company recognized VOBA of $4.00 billion and Other intangible assets of $449.8 million , which will be amortized over their estimated useful lives, ranging from 3 to 15 years, as well as indefinite-lived Other intangible assets of $11.6 million . Refer to Note 11 for additional information. Acquisition-related Costs Transaction costs related to the acquisition were expensed as incurred. These costs include advisory, legal, accounting, valuation and other professional or consulting fees, as well as general and administrative costs. Transaction costs incurred to date in connection with the acquisition of TWG totaled $39.3 million , including $24.8 million and $30.0 million for the three and six months ended June 30, 2018, respectively, which were reported through the Underwriting, general and administrative expenses line item in the consolidated statements of operations. As a part of the ongoing integration of TWG's operations, the Company has incurred, and will continue to incur, costs associated with restructuring the systems, processes and workforce. These costs include such items as severance, retention, facilities and consulting and other costs. Integration costs incurred to date in connection with the acquisition of TWG totaled $13.5 million , including $10.5 million and $12.8 million for the three and six months ended June 30, 2018, respectively, which were reported through the Underwriting, general and administrative expenses line item in the consolidated statements of operations. Financial Results The following table summarizes the results of the acquired TWG operations since the Acquisition Date that have been included within our consolidated statements of income (based on how TWG was allocated to the Company's reportable segments): June 1, 2018 to June 30, 2018 Global Lifestyle Corporate and Other (1) Total Total revenues $ 211.9 $ (1.6 ) $ 210.3 Net income $ 9.4 $ (0.1 ) $ 9.3 (1) The TWG operating results allocated to the Corporate and other segment consist of pre-tax integration expenses and net realized losses on investments, as offset by income tax benefits, which includes a $5.7 million tax structuring benefit. Refer to Note 19 - Income Taxes, for further information on the income tax benefit. Supplemental Pro Forma Information The following table provides unaudited supplemental pro forma consolidated information for the six months ended June 30, 2018 and 2017, as if TWG had been acquired as of January 1, 2017. The unaudited supplemental pro forma consolidated financial information is presented solely for informational purposes and is not necessarily indicative of the consolidated results of operations that might have been achieved had the transaction been completed as of the date indicated, nor are they meant to be indicative of any anticipated consolidated future results of operations that the combined company will experience after the transaction. Six Months Ended 2018 2017 Total revenues $ 4,519.1 $ 4,197.7 Net income $ 244.0 $ 282.5 Basic earnings per share $ 3.68 $ 4.13 Diluted earnings per share $ 3.64 $ 4.07 For the six months ended June 30, 2017, pro forma net income includes $19.4 million of nonrecurring transaction and integration costs, net of taxes. For the pro forma presentation, given the assumed acquisition date of January 1, 2017, transaction and integration costs that were incurred at, or subsequent to, the actual acquisition date have been included in the 2017 pro forma net income, whereas transaction and integration costs that were incurred prior to the actual acquisition date have been excluded from the 2017 pro forma net income. Prior year acquisition On February 1, 2017, the Company acquired 100% of Green Tree Insurance Holdings, Corp. and its subsidiaries Green Tree Insurance Agency and Green Tree Insurance Agency Reinsurance Limited (collectively “Green Tree”) for $125.0 million in cash with a potential earn-out of up to $25.0 million , based on future performance. Green Tree sells housing protection products, including voluntary homeowners’ and manufactured housing policies, and other insurance products. In connection with the acquisition, including measurement period adjustments, the Company recorded $10.4 million of net liabilities, $69.6 million of agency relationship and renewal rights intangible assets, all of which are amortizable over periods ranging from 7 to 16 years, and $65.8 million of goodwill, no

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information As of June 30, 2018, the Company had four reportable segments, which are defined based on the manner in which our Chief Operating Decision Makers (CEO and COO) review the business to assess performance and allocate resources, and align to the nature of the products and services offered: • Global Housing: provides lender-placed homeowners, manufactured housing and flood insurance; renters insurance and related products (referred to as multifamily housing); and valuation and field services (referred to as mortgage solutions). • Global Lifestyle: provides mobile device protection and related services and extended service products and related services (referred to as Connected Living); vehicle protection services (referred to as Global Automotive) and credit insurance and other insurance (referred to as Financial Services). • Global Preneed: provides pre-funded funeral insurance. • Total Corporate and Other: Corporate and Other includes activities of the holding company, financing and interest expenses, net realized gains (losses) on investments, interest income earned from short-term investments held and income (expenses) primarily related to the Company's frozen benefit plans. Corporate and Other also includes the amortization of deferred gains associated with the sales of Fortis Financial Group, Long-Term Care and Assurant Employee Benefits ("AEB") through reinsurance agreements, expenses related to the acquisition of TWG, and other unusual or infrequent items. Additionally, the Total Corporate and Other segment includes amounts related to the Assurant Health business, which is in runoff. As Assurant Health was a reportable segment in prior years, these amounts are disclosed separately in the following segment tables for comparability. The following tables summarize selected financial information by segment: Three Months Ended June 30, 2018 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 449.7 $ 874.3 $ 14.2 $ — $ 0.1 $ 0.1 $ 1,338.3 Fees and other income 92.8 227.9 32.7 0.6 0.2 0.8 354.2 Net investment income 15.9 36.6 67.9 14.6 0.6 15.2 135.6 Net realized gains on investments — — — (11.4 ) — (11.4 ) (11.4 ) Amortization of deferred gains on disposal of businesses (1) — — — 15.0 — 15.0 15.0 Total revenues 558.4 1,138.8 114.8 18.8 0.9 19.7 1,831.7 Benefits, losses and expenses Policyholder benefits (2) 187.2 239.3 65.0 — (0.9 ) (0.9 ) 490.6 Amortization of deferred acquisition costs and value of business acquired 50.4 395.6 17.2 — — — 463.2 Underwriting, general and administrative expenses 229.3 419.6 13.8 109.4 1.5 110.9 773.6 Interest expense — — — 26.0 — 26.0 26.0 Total benefits, losses and expenses 466.9 1,054.5 96.0 135.4 0.6 136.0 1,753.4 Segment income before provision for income tax 91.5 84.3 18.8 (116.6 ) 0.3 (116.3 ) 78.3 Provision for income taxes 18.9 16.2 4.1 (28.0 ) 0.1 (27.9 ) 11.3 Segment income after tax 72.6 68.1 14.7 (88.6 ) 0.2 (88.4 ) 67.0 Less: Preferred stock dividends — — — (4.8 ) — (4.8 ) (4.8 ) Net income attributable to common stockholders $ 72.6 $ 68.1 $ 14.7 $ (93.4 ) $ 0.2 $ (93.2 ) $ 62.2 As of June 30, 2018 Segment assets: $ 3,930.1 $ 20,561.5 $ 6,897.3 $ 10,911.2 $ 61.2 $ 10,972.4 $ 42,361.3 Three Months Ended June 30, 2017 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 442.4 $ 656.0 $ 15.2 $ — $ 1.7 $ 1.7 $ 1,115.3 Fees and other income 107.8 180.0 31.1 6.9 1.1 8.0 326.9 Net investment income 16.8 26.4 65.0 9.8 3.7 13.5 121.7 Net realized gains on investments — — — 13.2 — 13.2 13.2 Amortization of deferred gains on disposal of businesses (1) — — — 23.4 — 23.4 23.4 Total revenues 567.0 862.4 111.3 53.3 6.5 59.8 1,600.5 Benefits, losses and expenses Policyholder benefits (2) 188.2 178.1 61.9 — (11.8 ) (11.8 ) 416.4 Amortization of deferred acquisition costs and value of business acquired 46.8 283.6 16.3 — — — 346.7 Underwriting, general and administrative expenses 247.5 340.6 14.3 29.9 14.0 43.9 646.3 Interest expense — — — 12.4 — 12.4 12.4 Total benefits, losses and expenses 482.5 802.3 92.5 42.3 2.2 44.5 1,421.8 Segment income before provision for income tax 84.5 60.1 18.8 11.0 4.3 15.3 178.7 Provision for income taxes 28.3 19.9 6.0 3.5 0.8 4.3 58.5 Segment income after tax $ 56.2 $ 40.2 $ 12.8 $ 7.5 $ 3.5 $ 11.0 $ 120.2 Six Months Ended June 30, 2018 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 886.1 $ 1,547.9 $ 28.8 $ — $ 0.4 $ 0.4 $ 2,463.2 Fees and other income 179.5 472.8 64.3 1.8 0.3 2.1 718.7 Net investment income 36.1 68.7 133.7 25.6 1.7 27.3 265.8 Net realized gains on investments — — — (10.9 ) — (10.9 ) (10.9 ) Amortization of deferred gains on disposal of businesses (1) — — — 33.5 — 33.5 33.5 Total revenues 1,101.7 2,089.4 226.8 50.0 2.4 52.4 3,470.3 Benefits, losses and expenses Policyholder benefits (2) 356.3 420.9 131.7 — (3.7 ) (3.7 ) 905.2 Amortization of deferred acquisition costs and value of business acquired 100.0 675.9 33.7 — — — 809.6 Underwriting, general and administrative expenses 464.2 835.4 30.0 160.4 3.2 163.6 1,493.2 Interest expense — — — 47.5 — 47.5 47.5 Total benefits, losses and expenses 920.5 1,932.2 195.4 207.9 (0.5 ) 207.4 3,255.5 Segment income before provision for income tax 181.2 157.2 31.4 (157.9 ) 2.9 (155.0 ) 214.8 Provision for income taxes 37.4 33.3 6.9 (36.5 ) 0.7 (35.8 ) 41.8 Segment income after tax 143.8 123.9 24.5 (121.4 ) 2.2 (119.2 ) 173.0 Less: Preferred stock dividends — — — (4.8 ) — (4.8 ) (4.8 ) Net income attributable to common stockholders $ 143.8 $ 123.9 $ 24.5 $ (126.2 ) $ 2.2 $ (124.0 ) $ 168.2 Six Months Ended June 30, 2017 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 878.8 $ 1,251.8 $ 29.8 $ — $ 5.2 $ 5.2 $ 2,165.6 Fees and other income 203.1 389.1 60.7 11.8 2.4 14.2 667.1 Net investment income 36.0 52.9 129.2 19.4 4.8 24.2 242.3 Net realized gains on investments — — — 16.6 — 16.6 16.6 Amortization of deferred gains on disposal of businesses (1) — — — 60.4 — 60.4 60.4 Total revenues 1,117.9 1,693.8 219.7 108.2 12.4 120.6 3,152.0 Benefits, losses and expenses Policyholder benefits (2) 351.5 326.7 128.1 — (31.9 ) (31.9 ) 774.4 Amortization of deferred acquisition costs and value of business acquired 97.7 534.6 28.9 — — — 661.2 Underwriting, general and 488.2 695.3 29.2 57.5 27.4 84.9 1,297.6 Interest expense — — — 25.0 — 25.0 25.0 Total benefits, losses and expenses 937.4 1,556.6 186.2 82.5 (4.5 ) 78.0 2,758.2 Segment income before provision for income tax 180.5 137.2 33.5 25.7 16.9 42.6 393.8 Provision for income taxes 62.4 44.6 10.8 6.5 5.5 12.0 129.8 Segment income after tax $ 118.1 $ 92.6 $ 22.7 $ 19.2 $ 11.4 $ 30.6 $ 264.0 (1) The three months ended June 30, 2018 and 2017 include $12.7 million and $20.6 million , respectively, and the six months ended June 30, 2018 and 2017 include $29.0 million and $54.8 million , respectively, related to the amortization of deferred gains related to the 2016 sale of AEB. The remaining AEB unamortized deferred gain as of June 30, 2018 was $34.7 million . (2) The presentation of Assurant Health policyholder benefits includes the impact of the total current period net utilization of premium deficiency reserves for claim costs and claim adjustment expenses included in policyholder benefits, as well as maintenance costs, which are included within underwriting, general and administrative expenses. For the three months ended June 30, 2018 and 2017, the premium deficiency reserve liability decreased $0.7 million and $9.2 million , respectively, through an offset to policyholder benefit expense. For the six months ended June 30, 2018 and 2017, the premium deficiency reserve liability decreased $0.8 million and $21.9 million

Contract Revenues

Contract Revenues	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
Contracts Revenues	Contract Revenues Assurant partners with clients to provide consumers a diverse range of protection products and services. The Company’s revenues from protection products (approximately 80% of total revenues) are accounted for as insurance contracts and therefore are not subject to the new revenue standard adopted as of January 1, 2018 described in Note 3. Revenue from service contracts and sales of products (approximately 20% of total revenues) are recognized in accordance with the new revenue recognition standard. Specifically, these revenues are recognized as the contractual performance obligations are satisfied or the products are delivered. Revenue is measured as the amount of consideration we expect to be entitled to in exchange for performing the services or transferring products. If payments are received before the related revenue is recognized, the amount is recorded as unearned revenue or advance payment liabilities, until the performance obligations are satisfied or the products are transferred. The disaggregated revenues subject to the new revenue recognition standard and included in fees and other income on the consolidated statement of operations are $84.2 million and $160.3 million for Global Housing and $151.2 million and $324.8 million for Global Lifestyle for the three and six months ended June 30, 2018, respectively. Global Housing In our Global Housing segment, revenues from service contracts and sales of products are primarily from our mortgage solutions and lender-placed insurance businesses. Under our mortgage solutions business, we offer valuation and title services and products across the origination, home equity and default markets, as well as field services, inspection services, restoration and real estate owned (“REO”) asset management to mortgage servicing clients and investors. Under our lender-placed insurance business, we provide loan and claim payment tracking services for lenders. We generally invoice our customers weekly or monthly based on the volume of services provided during the billing period with payment due within a short-term period. Each service is an individual performance obligation with a standalone selling price. We recognize revenue as we invoice which corresponds with the value transferred to the customer. Global Lifestyle In our Global Lifestyle segment, revenue from service contracts and sales of products is primarily from our Connected Living business. Through partnerships with mobile carriers, we provide administrative services related to our mobile device protection products including program design and marketing strategy, risk management, data analytics, customer support and claims handling, supply chain and service delivery, repair and logistics, and device disposition. Administrative fees are generally billed monthly based on the volume of services provided during the billing period (for example, based on the number of mobile subscribers) with payment due within a short-term period. Each service or bundle of services, depending on the contract, is an individual performance obligation with a standalone selling price. We recognize revenue as we invoice which corresponds with the value transferred to the customer. We also sell repaired or refurbished mobile and other electronic devices. Revenue from products sold is recognized when risk of ownership transfers to customers, generally upon shipment. Each product has a standalone selling price that is determined through analysis of various factors including market data, historical costs and product lifecycle status. Payments are generally due prior to shipment or within a short-term period. Contract Balances The receivables and unearned revenue under these contracts were $134.9 million and $32.3 million , respectively, as of June 30, 2018. These balances are included in premiums and accounts receivable and the accounts payable and other liabilities, respectively, in the consolidated balance sheet. Revenue from service contracts and sales of products recognized during the three and six months ended June 30, 2018 that was included in unearned revenue as of December 31, 2017 was $4.5 million and $13.0 million , respectively. In certain circumstances, the Company pays up-front costs in connection with client contracts where the Company can demonstrate future economic benefit. The Company records such payments as intangible assets that are subject to periodic recoverability assessments based on the performance of the related contracts. As of June 30, 2018, the Company has approximately $13.6 million

Investments

Investments	6 Months Ended
	Jun. 30, 2018
Investments [Abstract]
Investments	Investments The following tables show the cost or amortized cost, gross unrealized gains and losses, fair value and other-than-temporary impairment (“OTTI”) included within accumulated other comprehensive income of the Company's fixed maturity securities as of the dates indicated: June 30, 2018 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value OTTI in AOCI (a) Fixed maturity securities: U.S. government and government agencies and authorities $ 184.1 $ 2.6 $ (2.1 ) $ 184.6 $ — States, municipalities and political subdivisions 461.6 17.9 (1.1 ) 478.4 — Foreign governments 858.4 62.8 (1.6 ) 919.6 — Asset-backed 494.7 1.2 (0.7 ) 495.2 — Commercial mortgage-backed 256.4 0.3 (2.8 ) 253.9 — Residential mortgage-backed 1,241.4 16.8 (21.4 ) 1,236.8 5.6 U.S. corporate 5,198.1 365.8 (43.7 ) 5,520.2 15.8 Foreign corporate 2,082.3 138.4 (11.9 ) 2,208.8 — Total fixed maturity securities $ 10,777.0 $ 605.8 $ (85.3 ) $ 11,297.5 $ 21.4 December 31, 2017 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value OTTI in AOCI (a) Fixed maturity securities: U.S. government and government agencies and authorities $ 180.6 $ 3.2 $ (1.2 ) $ 182.6 $ — States, municipalities and political subdivisions 302.3 24.0 (0.1 ) 326.2 — Foreign governments 524.8 72.3 (0.3 ) 596.8 — Asset-backed 188.4 1.9 (0.1 ) 190.2 1.0 Commercial mortgage-backed 38.6 0.2 (0.7 ) 38.1 — Residential mortgage-backed 1,084.2 32.5 (7.3 ) 1,109.4 9.2 U.S. corporate 4,774.2 602.1 (5.0 ) 5,371.3 17.4 Foreign corporate 1,663.4 188.6 (4.0 ) 1,848.0 — Total fixed maturity securities $ 8,756.5 $ 924.8 $ (18.7 ) $ 9,662.6 $ 27.6 Equity securities: Common stocks $ 9.3 $ 8.4 $ — $ 17.7 $ — Non-redeemable preferred stocks 307.0 43.8 (0.5 ) 350.3 — Total equity securities $ 316.3 $ 52.2 $ (0.5 ) $ 368.0 $ — (a) Represents the amount of OTTI recognized in AOCI. Amount includes unrealized gains and losses on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date. The Company's states, municipalities and political subdivisions holdings are highly diversified across the U.S., with no individual state’s exposure (including both general obligation and revenue securities) exceeding 0.5% and 0.4% of the overall investment portfolio as of June 30, 2018 and December 31, 2017, respectively. As of June 30, 2018 and December 31, 2017, the securities include general obligation and revenue bonds issued by states, cities, counties, school districts and similar issuers, including $98.3 million and $137.7 million , respectively, of advance refunded or escrowed-to-maturity bonds (collectively referred to as “pre-refunded bonds”), which are bonds for which an irrevocable trust has been established to fund the remaining payments of principal and interest. As of June 30, 2018 and December 31, 2017, revenue bonds account for 60% and 53% of the holdings, respectively. Excluding pre-refunded revenue bonds, the activities supporting the income streams of the Company’s revenue bonds are across a broad range of sectors, primarily education, health care, highway, water, airport and marina, specifically pledged tax revenues, and other miscellaneous sources such as bond banks, finance authorities and appropriations. The Company’s investments in foreign government fixed maturity securities are held mainly in countries and currencies where the Company has policyholder liabilities, which allow the assets and liabilities to be more appropriately matched. As of June 30, 2018, approximately 52% , 18% and 16% of the foreign government securities were held in Canadian government/provincials and the governments of Brazil and the United Kingdom, respectively. As of December 31, 2017, approximately 79% , 12% and 4% of the foreign government securities were held in Canadian government/provincials and the governments of Brazil and Germany, respectively. No other country represented more than 6% and 3% of the Company's foreign government securities as of June 30, 2018 and December 31, 2017, respectively. The Company has European investment exposure in its corporate fixed maturity securities of $785.2 million with a net unrealized gain of $31.4 million as of June 30, 2018 and $578.4 million with a net unrealized gain of $58.9 million as of December 31, 2017. Approximately 31% and 24% of the corporate fixed maturity European exposure is held in the financial industry as of June 30, 2018 and December 31, 2017, respectively. The Company's largest European country exposure (the United Kingdom) represented approximately 4% of the fair value of the Company's corporate fixed maturity securities as of June 30, 2018 and December 31, 2017. The Company's international investments are managed as part of the overall portfolio with the same approach to risk management and focus on diversification. The cost or amortized cost and fair value of fixed maturity securities as of June 30, 2018 by contractual maturity are shown below. Actual maturities may differ from contractual maturities because issuers of the securities may have the right to call or prepay obligations with or without call or prepayment penalties. Cost or Amortized Cost Fair Value Due in one year or less $ 320.5 $ 322.1 Due after one year through five years 2,276.5 2,294.7 Due after five years through ten years 2,314.2 2,338.8 Due after ten years 3,873.3 4,356.0 Total 8,784.5 9,311.6 Asset-backed 494.7 495.2 Commercial mortgage-backed 256.4 253.9 Residential mortgage-backed 1,241.4 1,236.8 Total $ 10,777.0 $ 11,297.5 The following table sets forth the net realized gains (losses), including OTTI, recognized in the statement of operations: Three Months Ended Six Months Ended 2018 2017 2018 2017 Net realized gains (losses) on investments: Fixed maturity securities $ (7.6 ) $ 11.9 $ (10.2 ) $ 14.5 Equity securities (1) (5.9 ) 1.5 (3.7 ) 3.8 Other investments 1.2 (0.1 ) 2.5 (1.2 ) Consolidated investment entities (2) 0.9 — 0.5 — Total net realized gains (losses) on investments (11.4 ) 13.3 (10.9 ) 17.1 Net realized losses related to other-than-temporary impairments: Fixed maturity securities — — — (0.4 ) Other investments — (0.1 ) — (0.1 ) Total net realized losses related to other-than- temporary impairments — (0.1 ) — (0.5 ) Total net realized gains (losses) $ (11.4 ) $ 13.2 $ (10.9 ) $ 16.6 (1) Six months ended June 30, 2018 includes a $7.8 million gain on one equity investment holding accounted for under the measurement alternative based on an observable market event where the implied value increased based on a new investment. Equity investments accounted for under the measurement alternative are included within Other investments on the consolidated balance sheet. (2) Consists of net realized losses from the change in fair value of the Company's direct investment in collateralized loan obligations ("CLOs"). Refer to Note 8 - Variable Interest Entities for further detail. The following table sets forth the portion of unrealized gains related to equity securities during the three and six months ended June 30, 2018: Three Months Ended Six Months Ended 2018 2018 Net losses recognized on equity securities $ (5.9 ) $ (3.7 ) Less: Net realized gains related to sales of equity securities 2.3 3.7 Total unrealized losses on equity securities held (1) $ (8.2 ) $ (7.4 ) (1) Net gains for 2018 are required to be reported through the income statement in accordance with the 2018 accounting guidance on financial instruments. Net unrealized gains of $9.0 million and $17.4 million in the three and six months ended June 30, 2017, respectively, were reported through AOCI. The carrying value of equity securities accounted for under the measurement alternative was $47.8 million and $36.1 million as of June 30, 2018 and December 31, 2017, respectively. The investment category and duration of the Company’s gross unrealized losses on fixed maturity securities as of June 30, 2018 and December 31, 2017 were as follows: June 30, 2018 Less than 12 months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: U.S. government and government agencies and authorities $ 112.7 $ (1.5 ) $ 35.9 $ (0.6 ) $ 148.6 $ (2.1 ) States, municipalities and political subdivisions 150.8 (0.9 ) 3.3 (0.2 ) 154.1 (1.1 ) Foreign governments 296.8 (1.4 ) 6.5 (0.2 ) 303.3 (1.6 ) Asset-backed 225.4 (0.7 ) — — 225.4 (0.7 ) Commercial mortgage-backed 181.1 (1.7 ) 12.0 (1.1 ) 193.1 (2.8 ) Residential mortgage-backed 677.9 (12.6 ) 161.1 (8.8 ) 839.0 (21.4 ) U.S. corporate 2,037.9 (40.9 ) 49.5 (2.8 ) 2,087.4 (43.7 ) Foreign corporate 760.7 (10.1 ) 63.6 (1.8 ) 824.3 (11.9 ) Total fixed maturity securities $ 4,443.3 $ (69.8 ) $ 331.9 $ (15.5 ) $ 4,775.2 $ (85.3 ) December 31, 2017 Less than 12 months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: U.S. government and government agencies and authorities $ 104.2 $ (0.7 ) $ 43.3 $ (0.5 ) $ 147.5 $ (1.2 ) States, municipalities and political subdivisions — — 2.4 (0.1 ) 2.4 (0.1 ) Foreign governments 24.4 (0.2 ) 0.8 (0.1 ) 25.2 (0.3 ) Asset-backed 27.6 (0.1 ) — — 27.6 (0.1 ) Commercial mortgage-backed — — 12.4 (0.7 ) 12.4 (0.7 ) Residential mortgage-backed 217.3 (2.4 ) 162.9 (4.9 ) 380.2 (7.3 ) U.S. corporate 562.8 (4.5 ) 30.0 (0.5 ) 592.8 (5.0 ) Foreign corporate 266.7 (3.5 ) 19.0 (0.5 ) 285.7 (4.0 ) Total fixed maturity securities $ 1,203.0 $ (11.4 ) $ 270.8 $ (7.3 ) $ 1,473.8 $ (18.7 ) Equity securities: Non-redeemable preferred stock $ 13.8 $ (0.2 ) $ 8.7 $ (0.3 ) $ 22.5 $ (0.5 ) Total gross unrealized losses represent approximately 2% and 1% of the aggregate fair value of the related securities with such unrealized losses as of June 30, 2018 and December 31, 2017, respectively. Approximately 82% and 61% of these gross unrealized losses have been in a continuous loss position for less than twelve months as of June 30, 2018 and December 31, 2017, respectively. The total gross unrealized losses are comprised of 3,145 and 679 individual securities as of June 30, 2018 and December 31, 2017, respectively. In accordance with its policy, the Company concluded that for these securities, other-than-temporary impairments of the gross unrealized losses was not warranted as of June 30, 2018 and December 31, 2017. The Company has entered into commercial mortgage loans, collateralized by the underlying real estate, on properties located throughout the U.S. and Canada. As of June 30, 2018, approximately 35% of the outstanding principal balance of commercial mortgage loans was concentrated in the states of California and Oregon, and the Canadian province of Ontario. Although the Company has a diversified loan portfolio, an economic downturn could have an adverse impact on the ability of its debtors to repay their loans. The outstanding balance of commercial mortgage loans range in size from less than $0.1 million to $12.6 million as of June 30, 2018 and less than $0.1 million to $12.7 million

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2018
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities In the normal course of business, the Company is involved with various types of investment entities which may be considered variable interest entities ("VIEs"). The Company evaluates its involvement with each entity to determine whether consolidation is required. The Company’s maximum risk of loss is limited to the carrying value and unfunded commitments of its investments in the VIEs. Consolidated VIEs One of our subsidiaries is registered with the U.S. Securities and Exchange Commission (the "SEC") as an investment adviser and manages and invests in CLOs and a real estate fund and may conduct other forms of investment activities. The Company determined the CLOs and real estate fund are VIEs and consolidated each because the Company was deemed to be the primary beneficiary of these entities due to (i) its role a s collateral manager, which gives it the power to direct the activities that most significantly impact the economic performance of the e ntities, and (ii) its economic interest in the entities, which exposes it to losses and the right to receive benefits that could potentially be significant to the entities. In connection with planned formation of CLO structures, the Company forms special purpose entities capitalized by contributions from the Company's wholly owned subsidiaries. Subsequent to capitalization, the special purpose entities purchase senior secured leveraged loans funded by contributions from the Company and a short-term warehousing credit facility. Borrowings from the warehousing credit facility are non-recourse to the Company and are fully repaid once the CLO closes. Additionally, the amounts contributed by the Company to fund the initial capitalization are returned after the CLO closes. The Company may elect to use the return of capital to purchase a direct investment in the CLO. Collateralized Loan Obligations: The CLO entities are collateralized financing entities. The carrying value of the CLO liabilities is equal to the fair value of the CLO assets (senior secured leveraged loans) as the assets have more observable fair values. The CLO liabilities are reduced by the beneficial interests the Company retains in the CLO. CLO earnings attributable to the Company’s shareholders are measured by the change in the fair value of the Company’s CLO investments, net investment income earned, and investment management and contingent performance fees earned. Investment management fees are reported as a reduction to investment expenses in the consolidated statements of operations. The assets of the CLOs are legally isolated from the creditors of the Company and can only be used to settle the obligations of the CLOs. The liabilities of the CLOs are non-recourse to the Company and the Company has no obligations to satisfy the liabilities of the CLOs. At June 30, 2018, the Company and its subsidiaries hold 6.0% of the most subordinated debt tranche of one CLO that closed in November 2017. In April 2018, a second CLO closed and the Company and its subsidiaries hold 9.4% of the most subordinated debt tranche of the CLO. At June 30, 2018, a third CLO structure was funded with $55.0 million in contributions and the fair value of borrowings from the short-term warehouse credit facilities was $174.3 million . The carrying value of the Company’s investment in the three CLOs was $116.2 million as of June 30, 2018. Real Estate Fund: Real estate fund earnings attributable to the Company’s shareholders are measured by the net investment income of the real estate fund, which includes the change in fair value of the Company’s investments in the real estate fund, and investment management fees earned. The Company has a majority investment in this fund in the form of an equity interest. The carrying value of the Company’s investment in the real estate fund was $83.6 million with unfunded commitments of $4.1 million as of June 30, 2018. For all consolidated investment entities, intercompany transactions are eliminated upon consolidation. Fair Value of VIE Assets and Liabilities The Company categorizes its fair value measurements according to a three-level hierarchy. See Note 9 for the definition of the three levels of the fair value hierarchy. The following table presents the balances of assets and liabilities held by consolidated investment entities measured at fair value on a recurring basis. Amounts presented are as of June 30, 2018 and December 31, 2017, respectively. June 30, 2018 Total Level 1 Level 2 Level 3 Financial Assets Investments: Cash and cash equivalents $ 35.0 $ 35.0 (1) $ — $ — Corporate debt securities 1,098.2 — 1,098.2 — Real estate fund 102.5 — — 102.5 Total financial assets $ 1,235.7 $ 35.0 $ 1,098.2 $ 102.5 Financial Liabilities Collateralized loan obligation notes $ 941.3 $ — $ 941.3 $ — Total financial liabilities $ 941.3 $ — $ 941.3 $ — December 31, 2017 Total Level 1 Level 2 Level 3 Financial Assets Investments: Cash and cash equivalents $ 54.5 $ 54.5 (1) $ — $ — Corporate debt securities 570.3 — 570.3 — Real estate fund 84.7 — — 84.7 Total financial assets $ 709.5 $ 54.5 $ 570.3 $ 84.7 Financial Liabilities Collateralized loan obligation notes $ 450.7 $ — $ 450.7 $ — Total financial liabilities $ 450.7 $ — $ 450.7 $ — (1) Amounts consist of money market funds. Level 2 Securities Corporate debt securities: These assets are comprised of senior secured leveraged loans. The Company values these securities using estimates of fair value from a pricing service which utilizes the market valuation technique. The primary observable market inputs used by the pricing service are prices of reported trades from dealers. The fair value is calculated using a simple average of the prices received. Collateralized loan obligation notes: As the Company elected the measurement alternative, the carrying value of the CLO liabilities is set equal to the fair value of the CLO assets. The CLO notes are classified within Level 2 of the fair value hierarchy, consistent with the classification of the majority of the CLO financial assets. Level 3 Securities Real estate fund: These assets are comprised of investments in limited partnerships whose underlying investments are real estate properties. The market, income and cost approach valuation techniques are used to calculate fair value as appropriate given the type of real estate property, as well as the use of independent external appraisals. Significant unobservable inputs, including capitalization rates, discount rates, market comparables, expense growth rates, leasing assumptions and replacement costs, are used as appropriate to calculate fair value. The following table summarizes the change in balance sheet carrying value associated with Level 3 assets held by consolidated investment entities measured at fair value during the three and six months ended June 30, 2018: Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Balance, beginning of period $ 86.8 $ 84.7 Purchases 23.0 23.0 Sales (6.8 ) (6.8 ) Total (loss) income included in earnings (0.5 ) 1.6 Balance, end of period $ 102.5 $ 102.5

Fair Value Disclosures

Fair Value Disclosures	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value Disclosures Fair Values, Inputs and Valuation Techniques for Financial Assets and Liabilities Disclosures The fair value measurements and disclosures guidance defines fair value and establishes a framework for measuring fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In accordance with this guidance, the Company has categorized its recurring fair value basis financial assets and liabilities into a three-level fair value hierarchy based on the priority of the inputs to the valuation technique. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and takes into account factors specific to the asset or liability. The levels of the fair value hierarchy are described below: • Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company can access. • Level 2 inputs utilize other than quoted prices included in Level 1 that are observable for the asset, either directly or indirectly, for substantially the full term of the asset. Level 2 inputs include quoted prices for similar assets in active markets, quoted prices for identical or similar assets in markets that are not active and inputs other than quoted prices that are observable in the marketplace for the asset. The observable inputs are used in valuation models to calculate the fair value for the asset. • Level 3 inputs are unobservable but are significant to the fair value measurement for the asset, and include situations where there is little, if any, market activity for the asset. These inputs reflect management’s own assumptions about the assumptions a market participant would use in pricing the asset. The Company reviews fair value hierarchy classifications on a quarterly basis. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The following tables present the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of June 30, 2018 and December 31, 2017. The amounts presented below for Other investments, Cash equivalents, Other assets, Assets and Liabilities held in separate accounts and Other liabilities differ from the amounts presented in the consolidated balance sheets because only certain investments or certain assets and liabilities within these line items are measured at estimated fair value. Other investments are comprised of investments in the Assurant Investment Plan, American Security Insurance Company Investment Plan, Assurant Deferred Compensation Plan, modified coinsurance arrangements and other derivatives. Other liabilities are comprised of investments in the Assurant Investment Plan, contingent considerations related to business combinations and other derivatives. The fair value amount and the majority of the associated levels presented for Other investments and Assets and Liabilities held in separate accounts are received directly from third parties. June 30, 2018 Total Level 1 Level 2 Level 3 Financial Assets Fixed maturity securities: U.S. government and government agencies and authorities $ 184.6 $ — $ 184.6 $ — State, municipalities and political subdivisions 478.4 — 478.4 — Foreign governments 919.6 0.6 919.0 — Asset-backed 495.2 — 450.1 45.1 Commercial mortgage-backed 253.9 — 194.0 59.9 Residential mortgage-backed 1,236.8 — 1,236.8 — U.S. corporate 5,520.2 — 5,484.8 35.4 Foreign corporate 2,208.8 — 2,158.2 50.6 Equity securities: Mutual funds 46.0 46.0 — — Common stocks 16.6 15.9 0.7 — Non-redeemable preferred stocks 323.2 — 321.0 2.2 Short-term investments 343.6 91.0 (2) 252.6 — Other investments 243.5 74.0 (1) 168.0 (3) 1.5 (4) Cash equivalents 637.5 469.0 (2) 168.5 (3) — Other assets 3.1 — 1.5 1.6 (5) Assets held in separate accounts 1,824.0 1,674.0 (1) 150.0 (3) — Total financial assets $ 14,735.0 $ 2,370.5 $ 12,168.2 $ 196.3 Financial Liabilities Other liabilities $ 119.4 $ 74.0 (1) $ — (5) $ 45.4 (6) Liabilities related to separate accounts 1,824.0 1,674.0 (1) 150.0 (3) — Total financial liabilities $ 1,943.4 $ 1,748.0 $ 150.0 $ 45.4 December 31, 2017 Total Level 1 Level 2 Level 3 Financial Assets Fixed maturity securities: U.S. government and government agencies and authorities $ 182.6 $ — $ 182.6 $ — State, municipalities and political subdivisions 326.2 — 326.2 — Foreign governments 596.8 1.0 595.8 — Asset-backed 190.2 — 150.8 39.4 Commercial mortgage-backed 38.1 — 9.5 28.6 Residential mortgage-backed 1,109.4 — 1,109.4 — U.S. corporate 5,371.3 — 5,350.2 21.1 Foreign corporate 1,848.0 — 1,802.7 45.3 Equity securities: Common stocks 17.7 17.0 0.7 — Non-redeemable preferred stocks 350.3 — 348.1 2.2 Short-term investments 284.1 141.6 (2) 142.5 — Other investments 253.9 71.2 (1) 172.7 (3) 10.0 (4) Cash equivalents 544.9 519.1 (2) 25.8 (3) — Other assets 2.1 — — 2.1 (5) Assets held in separate accounts 1,800.6 1,635.2 (1) 165.4 (3) — Total financial assets $ 12,916.2 $ 2,385.1 $ 10,382.4 $ 148.7 Financial Liabilities Other liabilities $ 128.7 $ 71.2 (1) $ 1.0 (5) $ 56.5 (6) Liabilities related to separate accounts 1,800.6 1,635.2 (1) 165.4 (3) — Total financial liabilities $ 1,929.3 $ 1,706.4 $ 166.4 $ 56.5 (1) Primarily includes mutual funds and related obligations. (2) Primarily includes money market funds. (3) Primarily includes fixed maturity securities and related obligations. (4) Primarily includes fixed maturity securities and other derivatives. (5) Primarily includes other derivative assets and liabilities. (6) Primarily includes contingent consideration liabilities related to business combinations and other derivatives. (7) Primarily includes fixed maturity securities and certificates of deposit. The following tables disclose the carrying value, fair value amount and hierarchy level of the financial instruments that are not carried at fair value in the consolidated balance sheets: June 30, 2018 Fair Value Carrying Value Total Level 1 Level 2 Level 3 Financial Assets Commercial mortgage loans on real estate $ 720.1 $ 716.0 $ — $ — $ 716.0 Other investments 94.7 94.7 35.0 — 59.7 Other assets 45.0 45.0 — — 45.0 Total financial assets $ 859.8 $ 855.7 $ 35.0 $ — $ 820.7 Financial Liabilities Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal) (1) $ 608.4 $ 608.5 $ — $ — $ 608.5 Funds withheld under reinsurance 347.1 347.1 347.1 — — Debt 2,004.8 2,084.9 — 2,084.9 — Total financial liabilities $ 2,960.3 $ 3,040.5 $ 347.1 $ 2,084.9 $ 608.5 December 31, 2017 Fair Value Carrying Value Total Level 1 Level 2 Level 3 Financial Assets Commercial mortgage loans on real estate $ 670.2 $ 679.2 $ — $ — $ 679.2 Other investments 84.4 84.4 36.3 — 48.1 Total financial assets $ 754.6 $ 763.6 $ 36.3 $ — $ 727.3 Financial Liabilities Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal) (1) $ 634.3 $ 642.5 $ — $ — $ 642.5 Funds withheld under reinsurance 179.8 179.8 179.8 — — Debt 1,068.2 1,174.4 — 1,174.4 — Total financial liabilities $ 1,882.3 $ 1,996.7 $ 179.8 $ 1,174.4 $ 642.5 (1) Only the fair value of the Company’s policy reserves for investment-type contracts (those without significant mortality or morbidity risk) are reflected in the table above. Reinsurance Recoverables Credit Disclosures A key credit quality indicator for reinsurance is the A.M. Best financial strength ratings of the reinsurer. The A.M. Best ratings are an independent opinion of a reinsurer’s ability to meet ongoing obligations to policyholders. The A.M. Best ratings for new reinsurance agreements where there is material credit exposure are reviewed at the time of execution. The A.M. Best ratings for existing reinsurance agreements are reviewed on a quarterly basis, or sooner based on developments. The A.M. Best ratings have not changed significantly since December 31, 2017, except for an increase in reinsurance recoverables that are included in the Not Rated category as a result of the acquisition of TWG. Specifically, legacy TWG reinsurance recoverables included $1.58 billion as of June 30, 2018 related to captive reinsurance arrangements with dealers which are substantially collateralized in the form of a letter of credit, trust account and funds withheld. An allowance for doubtful accounts for reinsurance recoverables is recorded on the basis of periodic evaluations of balances due from reinsurers (net of collateral), reinsurer solvency, management’s experience and current economic conditions. The Company carried an allowance for doubtful accounts for reinsurance recoverables of $0.3 million

Reserves

Reserves	6 Months Ended
	Jun. 30, 2018
Insurance Loss Reserves [Abstract]
Reserves	Reserves Reserve Roll Forward The following table provides a roll forward of the Company’s beginning and ending claims and benefits payable balances. Claims and benefits payable is the liability for unpaid loss and loss adjustment expenses and is comprised of case and incurred but not reported ("IBNR") reserves. Since unpaid loss and loss adjustment expenses are estimates, the Company’s actual losses incurred may be more or less than the Company’s previously developed estimates, which is referred to as either unfavorable or favorable development, respectively. The best estimate of ultimate loss and loss adjustment expense is generally selected from a blend of methods that are applied consistently each period. There have been no significant changes in the methodologies and assumptions utilized in estimating the liability for unpaid loss and loss adjustment expenses for any of the periods presented. For the Six Months Ended June 30, 2018 2017 Claims and benefits payable, at beginning of period $ 3,782.2 $ 3,301.2 Less: Reinsurance ceded and other (3,193.3 ) (2,718.2 ) Net claims and benefits payable, at beginning of period 588.9 583.0 Acquired reserves as of Acquisition Date (1) 142.9 — Incurred losses and loss adjustment expenses related to: Current year 938.1 856.3 Prior years (30.6 ) (60.0 ) Total incurred losses and loss adjustment expenses 907.5 796.3 Paid losses and loss adjustment expenses related to: Current year 624.6 556.0 Prior years 336.4 262.8 Total paid losses and loss adjustment expenses 961.0 818.8 Net claims and benefits payable, at end of period 678.3 560.5 Plus: Reinsurance ceded and other 2,824.8 2,532.8 Claims and benefits payable, at end of period $ 3,503.1 $ 3,093.3 (1) Acquired reserves from TWG on May 31, 2018 (the Acquisition Date) include $423.5 million of gross claims and benefits payable and $280.6 million of ceded claims and benefits payable. The reserve roll forward includes the activity of TWG from June 1, 2018 to June 30, 2018. The Company experienced favorable development in both six month periods presented in the roll forward table above. Favorable development in the six months ended June 30, 2018 was comparatively lower than the six months ended June 30, 2017. Global Housing and Global Lifestyle contributed $29.3 million and $51.7 million to the favorable development during the six months ended June 30, 2018 and 2017, respectively. Favorable development for Global Housing decreased in 2018 in part due to reduced favorable development on catastrophes. Favorable development on catastrophes was $2.2 million and $5.2 million for the six months ended June 30, 2018 and 2017, respectively. Excluding catastrophes, favorable development decreased for lender-placed homeowners products due to elevated severity on fire claims associated with prior periods and an increase in loss ratios associated with the runoff of REO policies. Favorable development for Global Lifestyle decreased in 2018 primarily from extended service contracts and credit insurance products, some of which is contractually subject to retrospective commission payments. The reduction was attributable to changing client mix, and consideration of prior development trends when finalizing year-end 2017 reserves. Another contributing factor to the reduction in favorable development in 2018 was from the continued runoff of the Assurant Health business. Assurant Health contributed $0.7 million in favorable development for the six months ended June 30, 2018 compared to $7.8 million

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Other Intangible Assets As a result of the May 2018 acquisition of TWG, the Company's Goodwill, VOBA and Other intangible assets increased. Refer to Note 4 - Acquisitions and disclosures below for additional information. Goodwill The Company has goodwill attributable to its Global Housing, Global Lifestyle and Global Preneed segments. A roll forward of goodwill by segment is provided below. Global Housing Global Lifestyle Global Preneed Consolidated Balance at December 31, 2017 (1) $ 386.7 $ 392.8 $ 138.2 $ 917.7 Acquisitions (2) — 1,463.8 — 1,463.8 Impairments (3) (8.1 ) — — (8.1 ) Foreign currency translation and other — (3.9 ) (0.3 ) (4.2 ) Balance at June 30, 2018 $ 378.6 $ 1,852.7 $ 137.9 $ 2,369.2 (1) Net of $1.26 billion of accumulated impairment losses. (2) Refer to Note 4 for additional information on the TWG acquisition. (3) Refer to Note 20 for additional information on the impairment loss on the mortgage solutions business. VOBA and Other Intangible Assets VOBA and Other intangible assets were $3,962.5 million and $664.8 million , respectively, at June 30, 2018 and $24.4 million and $288.6 million , respectively, at December 31, 2017. The increases reflect the additions from the TWG acquisition. The following table shows the preliminary purchase price allocation to VOBA and Other intangible assets and the related estimated useful lives. Amount Estimated Useful Life VOBA $ 3,995.7 9 years Finite life: Distribution network 392.4 15 years Technology based intangibles 57.4 9 years Total finite life other intangible assets 449.8 Indefinite life: Licenses $ 11.6 Indefinite Total other intangible assets $ 461.4 Total amortization of VOBA for the three months ended June 30, 2018 and 2017 was $36.3 million and $2.0 million , respectively, and for the six months ended June 30, 2018 and 2017 was $38.0 million and $4.1 million , respectively. Total amortization of Other intangible assets for the three months ended June 30, 2018 and 2017 was $19.7 million and $18.4 million , respectively, and for the six months ended June 30, 2018 and 2017 was $39.1 million and $36.3 million , respectively. At June 30, 2018, the estimated amortization of VOBA and Other intangible assets for the remainder of 2018, the next five years and thereafter is as follows: VOBA Other Intangible Assets (With Finite Lives) Related to TWG Acquisition Other Total Related to TWG Acquisition Other Total July 1 - December 31, 2018 $ 210.6 $ 3.5 $ 214.1 $ 7.3 $ 30.1 $ 37.4 2019 519.6 6.6 526.2 19.4 41.3 60.7 2020 632.2 6.3 638.5 27.6 35.4 63.0 2021 695.9 0.8 696.7 31.3 26.8 58.1 2022 759.4 0.7 760.1 35.0 17.3 52.3 2023 765.7 0.6 766.3 36.2 11.6 47.8 Thereafter 358.3 2.3 360.6 291.0 40.7 331.7 Total $ 3,941.7 $ 20.8 $ 3,962.5 $ 447.8 $ 203.2 $ 651.0

Debt

Debt	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Debt	Debt As of June 30, 2018, we had $2.00 billion of outstanding debt. In addition to the debt issuances described below, we have $350.0 million in senior notes due 2023 and $375.0 million in senior notes due 2034, as well as a $450 million senior revolving credit facility, of which no borrowings have been made. Debt Issuances Senior Notes: In March 2018, the Company issued three series of senior notes with an aggregate principal amount of $900.0 million . The first series of senior notes is $300.0 million in principal amount, bears floating interest rate equal to three-month LIBOR plus 1.25% and is payable in a single installment due March 2021 (the “2021 Senior Notes”). The second series is $300.0 million in principal amount, bears interest at 4.20% per year, is payable in a single installment due September 2023 and was issued at a 0.233% discount (the “2023 Senior Notes”). The third series is $300.0 million in principal amount, bears interest at 4.90% per year, is payable in a single installment due March 2028 and was issued at a 0.383% discount (the “2028 Senior Notes”). At any time in whole or from time to time in part, the Company may redeem the 2021 Senior Notes on or after March 2019, the 2023 Senior Notes prior to August 2023 and the 2028 Senior Notes prior to December 2027. Interest on the 2021 Senior Notes is payable quarterly in March, June, September and December of each year, beginning in June 2018. Interest on the 2023 Senior Notes and 2028 Senior Notes is payable semi-annually in March and September of each year, beginning in September 2018. The interest rate payable on any series of the Senior Notes will be subject to adjustment from time to time, if any of Moody’s Investor Service, Inc. or S&P Global Inc. downgrades the credit rating assigned to such series of Senior Notes to Ba1 or below or to BB+ or below, respectively, or subsequently upgrades the credit ratings once the Senior Notes are at or below such levels. The following table details the increase in interest rate over the issuance rate by rating with the impact equal to the sum of the number of basis points next to such rating for a maximum increase of 200 basis points over the issuance rate: Rating Agencies Rating Levels Moody's (1) S&P (1) Interest Rate Increase (2) 1 Ba1 BB+ 25 basis points 2 Ba2 BB 50 basis points 3 Ba3 BB- 75 basis points 4 B1 or below B+ or below 100 basis points (1) Including the equivalent ratings of any substitute rating agency. (2) Applies to each rating agency individually. Subordinated Notes: In March 2018, the Company issued subordinated notes due March 2048 with principal amount of $400.0 million (the “Subordinated Notes” and, together with the 2021 Senior Notes, 2023 Senior Notes and the 2028 Senior Notes, the “Notes”) which bear interest from March 2018 to March 2028, at an annual rate of 7.00% , payable semi-annually in March and September of each year, beginning in September 2018 and ending in March 2028. The Subordinated Notes will bear interest at an annual rate equal to three-month LIBOR plus 4.135% , payable quarterly in March, June, September and December of each year, beginning in June 2028. The Company may redeem the Subordinated Notes, in whole but not in part, at any time on or after March 2028 and prior to maturity at a redemption price set forth in the subordinated notes indenture, dated as of March 27, 2018 (the "Subordinated Notes Indenture"). At any time prior to March 2028, the Subordinated Notes will be redeemable in whole but not in part after the occurrence of a tax event, rating agency event or regulatory capital event as defined in the Subordinated Notes Indenture. In addition, the Company has the right, on one or more occasions, to defer the payment of interest on the Subordinated Notes for one or more consecutive interest periods for up to five years as described in the Subordinated Notes Indenture. At any time when the Company has given notice of its election to defer interest payments on the Subordinated Notes, the Company generally may not make payments on or redeem or purchase any shares of the Company’s capital stock or any of its debt securities or guarantees that rank upon our liquidation on a parity with or junior to the Subordinated Notes, subject to certain limited exceptions. The net proceeds from the sale of the Notes were $1.28 billion , after deducting the underwriting discounts and offering expenses. The Company used the proceeds from the Notes together with the proceeds from the issuance of its 6.50% Series D mandatory convertible preferred stock (“MCPS”), available cash on hand at closing and common stock consideration, to fund the TWG acquisition and pay related fees and expenses. A portion of the aggregate proceeds was used to repay the $350.0 million 2.50% senior notes upon maturity in March 2018. Term Loan and Bridge Loan Facilities In March 2018, the commitments under the Company's $1.50 billion senior unsecured bridge loan facility were terminated. In May 2018 the commitments under the Company's senior unsecured term loan facility were terminated. During the three and six months ended June 30, 2018, the Company incurred $0.3 million and $9.6 million , respectively, of expense related to the amortization of costs capitalized in connection with such facilities. Interest Rate Derivatives In March 2018, the Company exercised a series of derivative transactions it had entered into in 2017 to hedge the interest rate risk related to expected borrowing to finance the TWG acquisition. The Company determined that the derivatives qualified for hedge accounting as effective cash flow hedges and recognized a deferred gain of $26.7 million upon settlement that was reported through OCI. The deferred gain will be recognized as a reduction in interest expense related to the 2023 Senior Notes, 2028 Senior Notes and the Subordinated Notes on an effective yield basis, with $25.8 million remaining as of June 30, 2018. Additionally, the Company expensed $8.6 million of the premium paid for the derivatives as a component of interest expense for the six months ended June 30, 2018. In March 2018, the Company entered into a three-year interest rate swap under which the Company pays interest on $150.0 million of the 2021 Senior Notes at a fixed rate of 2.72%

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Certain amounts included in the consolidated statements of comprehensive income are net of reclassification adjustments. The following tables summarize those reclassification adjustments (net of taxes): Three Months Ended June 30, 2018 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at March 31, 2018 $ (272.3 ) $ 372.1 $ 21.1 $ 14.4 $ (83.6 ) $ 51.7 Change in accumulated other comprehensive (loss) income before reclassifications (83.1 ) (110.6 ) 0.5 (1.4 ) — (194.6 ) Amounts reclassified from accumulated other comprehensive (loss) income — 4.7 (0.7 ) — 1.0 5.0 Net current-period other comprehensive income (loss) (83.1 ) (105.9 ) (0.2 ) (1.4 ) 1.0 (189.6 ) Balance at June 30, 2018 $ (355.4 ) $ 266.2 $ 20.9 $ 13.0 $ (82.6 ) $ (137.9 ) Three Months Ended June 30, 2017 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at March 31, 2017 $ (300.3 ) $ 491.7 $ — $ 20.3 $ (63.4 ) $ 148.3 Change in accumulated other comprehensive (loss) income before reclassifications 15.7 80.9 — (1.5 ) — 95.1 Amounts reclassified from accumulated other comprehensive (loss) income — (7.0 ) — — 0.5 (6.5 ) Net current-period other comprehensive (loss) income 15.7 73.9 — (1.5 ) 0.5 88.6 Balance at June 30, 2017 $ (284.6 ) $ 565.6 $ — $ 18.8 $ (62.9 ) $ 236.9 Six Months Ended June 30, 2018 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at December 31, 2017 $ (281.5 ) $ 581.2 $ — $ 17.9 $ (83.6 ) $ 234.0 Change in accumulated other comprehensive (loss) income before reclassifications (73.9 ) (288.5 ) 21.6 (4.9 ) — (345.7 ) Amounts reclassified from accumulated other comprehensive (loss) income — 7.4 (0.7 ) — 1.0 7.7 Net current-period other comprehensive income (loss) (73.9 ) (281.1 ) 20.9 (4.9 ) 1.0 (338.0 ) Cumulative effect of change in accounting principles (1) — (33.9 ) — — — (33.9 ) Balance at June 30, 2018 $ (355.4 ) $ 266.2 $ 20.9 $ 13.0 $ (82.6 ) $ (137.9 ) Six Months Ended June 30, 2017 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at December 31, 2016 $ (322.1 ) $ 459.3 $ — $ 20.6 $ (63.2 ) $ 94.6 Change in accumulated other comprehensive (loss) income before reclassifications 37.5 117.1 — (1.8 ) — 152.8 Amounts reclassified from accumulated other comprehensive (loss) income — (10.8 ) — — 0.3 (10.5 ) Net current-period other comprehensive (loss) income 37.5 106.3 — (1.8 ) 0.3 142.3 Balance at June 30, 2017 $ (284.6 ) $ 565.6 $ — $ 18.8 $ (62.9 ) $ 236.9 (1) See Note 3 for additional information. The following tables summarize the reclassifications out of accumulated other comprehensive income for the three and six months ended June 30, 2018 and 2017: Details about accumulated other comprehensive income components Amount reclassified from accumulated other comprehensive income Affected line item in the statement where net income is presented Three Months Ended June 30, 2018 2017 Net unrealized gains on securities $ 6.0 $ (10.8 ) Net realized gains on investments, excluding other-than-temporary impairment losses (1.3 ) 3.8 Provision for income taxes $ 4.7 $ (7.0 ) Net of tax Unrealized gains on derivative transactions $ (0.9 ) $ — Interest Expense 0.2 — Provision for income taxes $ (0.7 ) $ — Net of tax Amortization of pension and postretirement unrecognized net periodic benefit cost: Amortization of net loss $ 1.2 $ 0.8 (1) (0.2 ) (0.3 ) Provision for income taxes $ 1.0 $ 0.5 Net of tax Total reclassifications for the period $ 5.0 $ (6.5 ) Net of tax Details about accumulated other comprehensive income components Amount reclassified from accumulated other comprehensive income Affected line item in the statement where net income is presented Six Months Ended June 30, 2018 2017 Net unrealized gains on securities $ 9.4 $ (16.7 ) Net realized gains on investments, excluding other-than-temporary impairment losses (2.0 ) 5.9 Provision for income taxes $ 7.4 $ (10.8 ) Net of tax Unrealized gains on derivative transactions $ (0.9 ) $ — Interest Expense 0.2 — Provision for income taxes $ (0.7 ) $ — Net of tax Amortization of pension and postretirement unrecognized net periodic benefit cost: Settlement gain $ — $ (0.6 ) Settlement gain Amortization of net loss 1.2 1.1 (1) 1.2 0.5 Total before tax (0.2 ) (0.2 ) Provision for income taxes $ 1.0 $ 0.3 Net of tax Total reclassifications for the period $ 7.7 $ (10.5 ) Net of tax (1)

Stock Based Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	Stock Based Compensation Under the Assurant, Inc. Long-Term Equity Incentive Plan (“ALTEIP”), as amended and restated in May 2017, the Company is authorized to issue up to 1,500,000 new shares of the Company's common stock to employees, officers and non-employee directors. Under the ALTEIP, the Company may grant awards based on shares of its common stock, including stock options, stock appreciation rights (“SARs”), restricted stock (including performance shares), unrestricted stock, restricted stock units (“RSUs”), performance share units (“PSUs”) and dividend equivalents. All share-based grants are awarded under the ALTEIP. Restricted Stock Units The following table shows a summary of RSU activity during the three and six months ended June 30, 2018 and 2017: Three Months Ended Six Months Ended 2018 2017 2018 2017 RSU compensation expense $ 8.7 $ 6.1 $ 13.8 $ 10.8 Income tax benefit (1.5 ) (2.1 ) (2.3 ) (3.8 ) RSU compensation expense, net of tax $ 7.2 $ 4.0 $ 11.5 $ 7.0 RSUs granted 32,330 31,554 421,829 205,199 Weighted average grant date fair value per unit $ 89.56 $ 99.74 $ 90.64 $ 99.17 Total fair value of vested RSUs $ 2.6 $ 3.5 $ 18.8 $ 23.9 As of June 30, 2018, there was $39.4 million of unrecognized compensation cost related to outstanding RSUs. That cost is expected to be recognized over a weighted-average period of 1.5 years. Performance Share Units The following table shows a summary of PSU activity during the three and six months ended June 30, 2018 and 2017: Three Months Ended Six Months Ended 2018 2017 2018 2017 PSU compensation expense $ 3.1 $ 3.2 $ 7.3 $ 0.1 Income tax benefit (0.4 ) (1.1 ) (1.3 ) — PSU compensation expense, net of tax $ 2.7 $ 2.1 $ 6.0 $ 0.1 PSUs granted — — — 237,623 Weighted average grant date fair value per unit $ — $ — $ — $ 112.32 Total fair value of vested PSUs $ 25.6 $ 29.4 $ 25.6 $ 29.4 Portions of the compensation expense recorded in prior years were reversed in the three and six months ended June 30, 2017 related to the Company’s level of actual performance as measured against pre-established performance goals and peer group results. As of June 30, 2018, there was $14.1 million of unrecognized compensation cost related to outstanding PSUs. That cost is expected to be recognized over a weighted-average period of 0.8 year. The fair value of PSUs with market conditions was estimated on the date of grant using a Monte Carlo simulation model, which utilizes multiple variables that determine the probability of satisfying the market condition stipulated in the award. Expected volatilities for awards issued during the six months ended June 30, 2017 were based on the historical stock prices of the Company’s stock and peer group. The expected term for grants issued during the six months ended June 30, 2017 was assumed to equal the average of the vesting period of the PSUs. The risk-free rate was based on the U.S. Treasury yield curve in effect at the time of grant. In March 2018, the Compensation Committee of the Company’s Board of Directors granted RSUs to the Company’s management committee, including its named executive officers. The RSUs had a three-year annual vesting schedule and reflected half of each executive’s annual target long-term incentive opportunity. The Compensation Committee elected to wait to grant PSUs to the management committee until the closing of the TWG acquisition in order to align the performance metrics for the PSUs with the Company’s expectations regarding its post-closing financial performance. In July 2018, the Compensation Committee granted PSUs to the management committee that reflect the remaining half of each executive’s annual target long-term incentive opportunity plus an additional opportunity to further incentivize and retain executives with respect to the TWG acquisition. Payout for the PSUs is determined by reference to two metrics measured over a thirty-month performance period: (i) total shareholder return relative to the S&P 500 Index (weighted at 60%) and (ii) the realization of net pre-tax synergies in connection with the TWG acquisition (weighted at 40%) provided that a net operating earnings per share (excluding catastrophes) goal is met in 2020. The aggregate grant date fair value of the additional target opportunity provided to all members of the management committee, including the Company’s CEO and other named executive officers, was $11.1 million . The additional target opportunity granted to the Company’s CEO had a grant date fair value of $4.0 million

Equity Transactions

Equity Transactions	6 Months Ended
	Jun. 30, 2018
Class of Stock Disclosures [Abstract]
Equity Transactions	Equity Transactions Stock Repurchase There were no share repurchases during the six months ended June 30, 2018. As of June 30, 2018, $293.4 million remains under the total repurchase authorization. The Company repurchased 2,209,636 shares of the Company’s outstanding common stock at a cost of $216.3 million during the six months ended June 30, 2017, exclusive of commissions. The timing and the amount of future repurchases will depend on market conditions, the Company's financial condition, results of operations, liquidity and other factors. Issuance of Mandatory Convertible Preferred Stock In March 2018, the Company issued 2,875,000 shares of the MCPS, with a par value of $1.00 per share at a public offering price of $100.00 per share and liquidation preference of $100.00 per share, which included the underwriters' exercise in full of their option to purchase 375,000 additional shares of MCPS to cover over-allotments. The net proceeds from the sale of the MCPS was $276.4 million after deducting the underwriting discounts and offering expenses. Refer to Note 12 for further details on the use of proceeds from this offering. Each outstanding share of MCPS will convert automatically on March 15, 2021 (the "mandatory conversion date") into between 0.9354 and 1.1225 shares of common stock (respectively, the “minimum conversion rate” and “maximum conversion rate”), subject to customary anti-dilution adjustments. The number of shares of our common stock issuable on conversion of the MCPS will be determined based on the average volume weighted average price per share of our common stock over the 20 consecutive trading day period preceding the mandatory conversion date. At any time prior to March 2021, holders may elect to convert each share of the MCPS into shares of common stock at the minimum conversion rate or in the event of a fundamental change at the specified rates as defined in the certificate of designations of the MCPS. Dividends on our MCPS will be payable on a cumulative basis when, as and if declared, at an annual rate of 6.50% of the liquidation preference of $100.00 per share. The first dividend of $1.6792 per share of the MCPS, or $4.8 million in total, was paid in cash on June 15, 2018. Each subsequent dividend is expected to be $1.6250 per share of the MCPS. On July 12, 2018, the board declared a dividend of $1.6250

Earnings Per Common Share

Earnings Per Common Share	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share The following table presents net income, the weighted average common shares used in calculating basic earnings per common share (“EPS”) and those used in calculating diluted EPS for each period presented below. Diluted EPS reflects the incremental common shares from: (1) shares issuable upon vesting of PSUs and ESPP using the treasury stock method; and (2) shares issuable upon conversion of the MCPS using the if-converted method. Refer to Note 14 - Stock Based Compensation and Note 15 - Equity Transactions for further information regarding potential common share issuances. The outstanding RSUs have non-forfeitable rights to dividend equivalents and are therefore included in calculating basic and diluted EPS under the two-class method. Three Months Ended Six Months Ended 2018 2017 2018 2017 Numerator Net income $ 67.0 $ 120.2 $ 173.0 $ 264.0 Less: Preferred stock dividends (4.8 ) — (4.8 ) — Net income attributable to common stockholders 62.2 120.2 168.2 264.0 Less: Common stock dividends paid (30.9 ) (30.3 ) (60.6 ) (60.0 ) Undistributed earnings $ 31.3 $ 89.9 $ 107.6 $ 204.0 Denominator Weighted average shares outstanding used in basic earnings per share 57,060,313 55,230,367 55,125,584 55,713,172 Incremental common shares from: PSUs 163,596 239,400 217,455 321,849 ESPP 40,499 40,131 40,499 40,131 MCPS — — 1,889,890 — Weighted average shares used in diluted earnings per share calculations 57,264,408 55,509,898 57,273,428 56,075,152 Earnings per common share - Basic Distributed earnings $ 0.54 $ 0.55 $ 1.10 $ 1.08 Undistributed earnings 0.55 1.63 1.95 3.66 Net income attributable to common stockholders $ 1.09 $ 2.18 $ 3.05 $ 4.74 Earnings per common share - Diluted Distributed earnings $ 0.54 $ 0.54 $ 1.06 $ 1.07 Undistributed earnings 0.55 1.62 1.96 3.64 Net income attributable to common stockholders $ 1.09 $ 2.16 $ 3.02 $ 4.71 Average PSUs totaling 4,171 and 97,574 for the three months ended June 30, 2018 and 2017, respectively, and 4,171 and 74,410 for the six months ended June 30, 2018 and 2017, respectively, were anti-dilutive and thus not included in the computation of diluted EPS under the treasury stock method. Average MCPS totaling 3,056,700

Retirement and Other Employee B

Retirement and Other Employee Benefits	6 Months Ended
	Jun. 30, 2018
Defined Benefit Plan [Abstract]
Retirement and Other Employee Benefits	Retirement and Other Employee Benefits The components of net periodic benefit cost for the Company’s qualified pension benefits plan, nonqualified pension benefits plan and retirement health benefits plan for the three and six months ended June 30, 2018 and 2017 were as follows: Qualified Pension Benefits Unfunded Nonqualified Pension Benefits Retirement Health Benefits For the Three Months Ended June 30, For the Three Months Ended June 30, For the Three Months Ended June 30, 2018 2017 Plan 1 2017 Plan 2 2018 2017 2018 2017 Interest cost 5.8 2.9 3.1 0.7 0.7 0.9 0.8 Expected return on plan assets (9.1 ) (6.1 ) (6.8 ) — — (0.6 ) (0.7 ) Amortization of net loss 0.2 — 0.3 0.3 0.3 — — Net periodic benefit cost $ (3.1 ) $ (3.2 ) $ (3.4 ) $ 1.0 $ 1.0 $ 0.3 $ 0.1 Qualified Pension Benefits Unfunded Nonqualified Pension Benefits Retirement Health Benefits For the Six Months Ended June 30, For the Six Months Ended June 30, For the Six Months Ended June 30, 2018 2017 Plan 1 2017 Plan 2 2018 2017 2018 2017 Interest cost $ 11.6 $ 5.8 $ 6.2 $ 1.4 $ 1.5 $ 1.7 $ 1.7 Expected return on plan assets (18.2 ) (12.2 ) (13.6 ) — — (1.1 ) (1.5 ) Amortization of net loss 0.4 — 0.6 0.8 0.6 — — Curtailment/settlement gain — — — — (0.7 ) — — Net periodic benefit cost $ (6.2 ) $ (6.4 ) $ (6.8 ) $ 2.2 $ 1.4 $ 0.6 $ 0.2 Assurant's qualified and non-qualified pension benefit plans were frozen on March 1, 2016. Effective December 31, 2017 Assurant Pension Plan No. 1 ("Plan No. 1") and Assurant Pension Plan No. 2 ("Plan No. 2") were merged into the Assurant Pension Plan (the "Plan"). The expected long-term return on plan assets for 2018 is 4.75% , reflecting a decrease from 6.75% in 2017 due to the reallocation of plan assets through 2018. The Plan's funded status increased to $83.7 million at June 30, 2018 from $81.3 million (based on the fair value of the assets compared to the accumulated benefit obligation) at December 31, 2017. This equates to a 112% and 111% funded status at June 30, 2018 and December 31, 2017, respectively. No cash was contributed to the Plan during the first six months of 2018. Due to the Plan's current funded status, no

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Letters of Credit In the normal course of business, letters of credit are issued primarily to support reinsurance arrangements in which the Company is the reinsurer. These letters of credit are supported by commitments under which the Company is required to indemnify the financial institution issuing the letter of credit if the letter of credit is drawn. The Company had $16.9 million and $18.1 million of letters of credit outstanding as of June 30, 2018 and December 31, 2017, respectively. Legal and Regulatory Matters The Company is involved in a variety of litigation relating to its current and past business operations and, from time to time, it may become involved in other such actions. In particular, the Company is a defendant in class actions in a number of jurisdictions regarding its lender-placed insurance programs. These cases assert a variety of claims under a number of legal theories. The plaintiffs seek premium refunds and other relief. The Company continues to defend itself vigorously in these class actions. We have participated and may participate in settlements on terms that we consider reasonable given the strength of our defenses and other factors. The Company has established an accrued liability for various legal and regulatory proceedings. However, the possible loss or range of loss resulting from such litigation and regulatory proceedings, if any, in excess of the amounts accrued is inherently unpredictable and uncertain. Consequently, no estimate can be made of any possible loss or range of loss in excess of the accrual. Although the Company cannot predict the outcome of any pending legal or regulatory action, or the potential losses, fines, penalties or equitable relief, if any, that may result, it is possible that such outcome could have a material adverse effect on the Company’s consolidated results of operations or cash flows for an individual reporting period. However, on the basis of currently available information, management does not believe that the pending matters are likely to have a material adverse effect, individually or in the aggregate, on the Company’s financial condition. Guaranty Fund Assessments Under state guaranty association laws, certain insurance companies can be assessed (up to prescribed limits) for certain obligations to the policyholders and claimants of impaired or insolvent insurance companies that write the same line or similar lines of business. In 2009, the Pennsylvania Insurance Commissioner (the “Commissioner”) placed long-term care insurer Penn Treaty Network America Insurance Company and one of its subsidiaries (collectively, “Penn Treaty”) in rehabilitation, an intermediate action before insolvency, and subsequently petitioned a state court to convert the rehabilitation into a liquidation. The state court began a hearing in July 2015 to consider the Commissioner’s most recent proposed rehabilitation plan, which contemplates a partial liquidation of Penn Treaty. In March 2017, the order of liquidation was granted. During the six months ended June 30, 2018 and 2017, the Company accrued an additional $1.4 million and $0.8 million of expense, respectively, related to Penn Treaty due to a revised estimated total loss liability and has a net liability of $6.3 million

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In connection with the initial analysis of the impact of the U.S. Tax Cuts and Jobs Act ("TCJA"), the Company recorded net discrete provision tax reform adjustments of $177.0 million and $(6.0) million for Assurant (pre-closing) and TWG, respectively, as of December 31, 2017. As of June 30, 2018, the Company has no revisions to the initial estimates and does not expect to finalize the analysis until the 2017 U.S. corporate income tax return is filed later in 2018. During the three and six months ended June 30, 2018, the Company recorded net tax benefits of $3.9 million in the Global Lifestyle segment, as a result of changes in estimates related to international taxes, and $5.7 million

Dispositions

Dispositions	6 Months Ended
	Jun. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Dispositions	Dispositions On August 1, 2018, the Company sold its mortgage solutions business to Xome, an indirectly wholly owned subsidiary of WMIH Corp., for cash consideration of $35.0 million and potential future payments based on revenue retention targets and certain types of new business. The sale includes Assurant Services, LLC and its wholly owned subsidiaries Assurant Field Services, Assurant Valuations Originations, Assurant Valuations Default and Assurant Title. The Company has entered into a transition services agreement to provide ongoing services for one year for fees approximating the cost of such services. As of June 30, 2018, the Company recorded a pre-tax impairment loss of $43.5 million , when comparing the net assets of the mortgage solutions businesses held for sale to the estimated fair value less selling costs. The loss is classified in Underwriting, general and administrative expenses in the consolidated statements of operations.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying unaudited interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. Accordingly, these statements do not include all of the information and notes required by GAAP for complete financial statements. The consolidated financial statements include the results of TWG from June 1, 2018. The interim financial data as of June 30, 2018 and for the three and six months ended June 30, 2018 and 2017 is unaudited; in the opinion of management, the interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods. The unaudited interim consolidated financial statements include the accounts of the Company and all of its wholly owned subsidiaries. All inter-company transactions and balances are eliminated in consolidation.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted Revenue recognition from contracts with customers: On January 1, 2018, the Company adopted the new guidance related to revenue recognition from contracts with customers. The new guidance was adopted using the modified retrospective approach, whereby the cumulative effect of adoption to retained earnings was recognized as of January 1, 2018 and the comparative information was not restated and continues to be reported under the accounting standards in effect for those periods. The guidance affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards. Insurance and similar contracts issued by insurance entities are specifically excluded from the scope of the amended revenue recognition guidance. As such, this standard only applies to the Company’s service contracts and sales of products, including those related to providing administrative services, mobile device related services, mortgage property risk management services and similar fee for service arrangements. Revenues from these contracts correspond to approximately 20% of the Company’s total 2017 revenues. The standard utilizes a five-step approach that emphasizes the recognition of revenue when the performance obligations are met by the Company in order to reflect the transfer of promised goods or services to customers in an amount that reflects the consideration the Company expects to receive. As of the adoption date, accounts payable and other liabilities decreased by $10.0 million , other assets decreased by $0.3 million , retained earnings increased by $7.5 million , and deferred taxes increased by $2.2 million due to a change in the revenue recognition associated with certain mobile upgrade programs. The change reflects the recognition of upgrade revenue in proportion to the pattern of rights expected to be exercised as opposed to recognition when the event (upgrade or end of term) occurs. The comparable mobile upgrade programs impacted by this change were immaterial in prior periods. Upon adoption of the new revenue recognition guidance, the Company’s revenues for service contracts and sales of products are subject to additional disclosure requirements, such as those related to providing disaggregated revenue disclosure, changes in contract balances, enhanced description of performance obligations, basis of determining costs and related significant judgments used in determining appropriate revenue recognition procedures. Refer to Note 6 for the Contract Revenues note. Financial instruments measurement and classification: On January 1, 2018, the Company adopted the amended guidance on the measurement and classification of financial instruments whereby all common and preferred stocks are measured at fair value through the income statement. Upon adoption, the Company recorded a cumulative effect adjustment to increase retained earnings by $33.9 million , which represents a reclassification from AOCI of the unrealized gains on common and preferred stock as of the date of adoption. The Company's other-than-temporary impairment policies have been updated to reflect that the change in value for preferred and common stocks are now reported in net income. For certain private equity investments recorded in Other investments, the Company elected the measurement alternative to record these investments at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer. The measurement alternative has been applied on a prospective basis. Income tax consequences for intra-entity transfers of assets: On January 1, 2018, the Company adopted the amended guidance on tax accounting for intra-entity transfers of assets. The amended guidance requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs as opposed to when it has been sold to an outside party. Also, the amended guidance eliminates the exception for an intra-entity transfer of an asset other than inventory. The adoption of this amended guidance did not have an impact on the Company’s financial position and results of operations. Statement of cash flows presentation and classification: On January 1, 2018, the Company adopted the amended guidance on presentation and classification in the statement of cash flows. The amended guidance addresses certain specific cash flow issues including debt prepayment and debt extinguishment costs; settlement of zero-coupon or insignificant coupon debt instruments; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (including bank-owned life insurance policies); distributions received from equity method investees; beneficial interests in securitization transactions; and guidance related to the identification of the primary source for separately identifiable cash flows. The adoption of this amended guidance did not have an impact on the Company’s financial position and results of operations. Accounting for hedging activities : On January 1, 2018, the Company adopted the amended guidance related to hedge effectiveness testing requirements, income statement presentation and disclosure and hedge accounting qualification criteria. The amended guidance requires that realized gains and losses on forecasted transactions are recorded in the financial statement line item to which the underlying forecasted transactions relates; simplifies the ongoing effectiveness testing; and reduces the complexity of hedge accounting requirements for new derivative contracts. The adoption of this amended guidance did not have a material impact on the Company's financial position and results of operations. Not Yet Adopted Classification of certain tax effects from accumulated other comprehensive income: In February 2018, the Financial Accounting Standards Board ("FASB") issued amended guidance on reclassifying the stranded tax effects from the Tax Cuts and Jobs Act of 2017 from accumulated other comprehensive income to retained earnings. The amended guidance is effective in fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Therefore, the Company is required to adopt the guidance on January 1, 2019. Early adoption is permitted, including adoption in any interim period for reporting periods in which financial statements have not yet been issued. The amendments in this guidance should be applied either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act is recognized. The adoption of this amended guidance will not have a material impact on the Company's financial position and results of operations. Reporting credit losses of assets held at amortized cost : In June 2016, the FASB issued amended guidance on reporting credit losses for assets held at amortized cost and available for sale debt securities. For assets held at amortized cost, the amended guidance eliminates the probable recognition threshold and instead requires an entity to reflect the current estimate of all expected credit losses. For available for sale debt securities, credit losses will be measured in a manner similar to current accounting requirements; however, the amended guidance requires that credit losses be presented as an allowance rather than as a permanent impairment. The amendments affect loans, debt securities, trade receivables, net investments in leases, off balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. The amended guidance is effective in fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Therefore, the Company is required to adopt the guidance on January 1, 2020. Early adoption is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is evaluating the requirements of this amended guidance and the potential impact on the Company’s financial position and results of operations. Lease accounting

Acquisitions Acquisitions (Tabl

Acquisitions Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The table below details the purchase consideration: Calculation of acquisition consideration Common stock shares issued to TWG equityholders 10,399,862 Volume weighted average common share price of Assurant, Inc. on May 31, 2018 $ 93.80 Share issuance consideration $ 975.5 Aggregate cash consideration 894.9 Repayment of pre-existing TWG debt 595.9 Total acquisition consideration $ 2,466.3
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	Preliminary estimate of assets acquired and (liabilities) assumed Fixed maturity securities available for sale $ 2,359.3 Equity securities 49.4 Short-term investments 174.5 Other investments 104.2 Cash and cash equivalents 277.3 Premiums and accounts receivable, net 275.2 Reinsurance recoverables 1,917.5 Accrued investment income 31.6 Property and equipment 15.4 Value of business acquired 3,995.7 Other intangible assets 461.4 Other assets 195.5 Unearned premiums and contract fees (7,250.7 ) Claims and benefits payable (423.5 ) Reinsurance balances payable (186.1 ) Funds held under reinsurance (200.8 ) Accounts payable and other liabilities (791.6 ) Non-controlling interest (1.8 ) Total identifiable net assets acquired 1,002.5 Goodwill 1,463.8 Total acquisition consideration $ 2,466.3
Business Acquisition, Pro Forma Information	The following table summarizes the results of the acquired TWG operations since the Acquisition Date that have been included within our consolidated statements of income (based on how TWG was allocated to the Company's reportable segments): June 1, 2018 to June 30, 2018 Global Lifestyle Corporate and Other (1) Total Total revenues $ 211.9 $ (1.6 ) $ 210.3 Net income $ 9.4 $ (0.1 ) $ 9.3 (1) The TWG operating results allocated to the Corporate and other segment consist of pre-tax integration expenses and net realized losses on investments, as offset by income tax benefits, which includes a $5.7 million Six Months Ended 2018 2017 Total revenues $ 4,519.1 $ 4,197.7 Net income $ 244.0 $ 282.5 Basic earnings per share $ 3.68 $ 4.13 Diluted earnings per share $ 3.64 $ 4.07

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Financial Information by Segment	The following tables summarize selected financial information by segment: Three Months Ended June 30, 2018 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 449.7 $ 874.3 $ 14.2 $ — $ 0.1 $ 0.1 $ 1,338.3 Fees and other income 92.8 227.9 32.7 0.6 0.2 0.8 354.2 Net investment income 15.9 36.6 67.9 14.6 0.6 15.2 135.6 Net realized gains on investments — — — (11.4 ) — (11.4 ) (11.4 ) Amortization of deferred gains on disposal of businesses (1) — — — 15.0 — 15.0 15.0 Total revenues 558.4 1,138.8 114.8 18.8 0.9 19.7 1,831.7 Benefits, losses and expenses Policyholder benefits (2) 187.2 239.3 65.0 — (0.9 ) (0.9 ) 490.6 Amortization of deferred acquisition costs and value of business acquired 50.4 395.6 17.2 — — — 463.2 Underwriting, general and administrative expenses 229.3 419.6 13.8 109.4 1.5 110.9 773.6 Interest expense — — — 26.0 — 26.0 26.0 Total benefits, losses and expenses 466.9 1,054.5 96.0 135.4 0.6 136.0 1,753.4 Segment income before provision for income tax 91.5 84.3 18.8 (116.6 ) 0.3 (116.3 ) 78.3 Provision for income taxes 18.9 16.2 4.1 (28.0 ) 0.1 (27.9 ) 11.3 Segment income after tax 72.6 68.1 14.7 (88.6 ) 0.2 (88.4 ) 67.0 Less: Preferred stock dividends — — — (4.8 ) — (4.8 ) (4.8 ) Net income attributable to common stockholders $ 72.6 $ 68.1 $ 14.7 $ (93.4 ) $ 0.2 $ (93.2 ) $ 62.2 As of June 30, 2018 Segment assets: $ 3,930.1 $ 20,561.5 $ 6,897.3 $ 10,911.2 $ 61.2 $ 10,972.4 $ 42,361.3 Three Months Ended June 30, 2017 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 442.4 $ 656.0 $ 15.2 $ — $ 1.7 $ 1.7 $ 1,115.3 Fees and other income 107.8 180.0 31.1 6.9 1.1 8.0 326.9 Net investment income 16.8 26.4 65.0 9.8 3.7 13.5 121.7 Net realized gains on investments — — — 13.2 — 13.2 13.2 Amortization of deferred gains on disposal of businesses (1) — — — 23.4 — 23.4 23.4 Total revenues 567.0 862.4 111.3 53.3 6.5 59.8 1,600.5 Benefits, losses and expenses Policyholder benefits (2) 188.2 178.1 61.9 — (11.8 ) (11.8 ) 416.4 Amortization of deferred acquisition costs and value of business acquired 46.8 283.6 16.3 — — — 346.7 Underwriting, general and administrative expenses 247.5 340.6 14.3 29.9 14.0 43.9 646.3 Interest expense — — — 12.4 — 12.4 12.4 Total benefits, losses and expenses 482.5 802.3 92.5 42.3 2.2 44.5 1,421.8 Segment income before provision for income tax 84.5 60.1 18.8 11.0 4.3 15.3 178.7 Provision for income taxes 28.3 19.9 6.0 3.5 0.8 4.3 58.5 Segment income after tax $ 56.2 $ 40.2 $ 12.8 $ 7.5 $ 3.5 $ 11.0 $ 120.2 Six Months Ended June 30, 2018 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 886.1 $ 1,547.9 $ 28.8 $ — $ 0.4 $ 0.4 $ 2,463.2 Fees and other income 179.5 472.8 64.3 1.8 0.3 2.1 718.7 Net investment income 36.1 68.7 133.7 25.6 1.7 27.3 265.8 Net realized gains on investments — — — (10.9 ) — (10.9 ) (10.9 ) Amortization of deferred gains on disposal of businesses (1) — — — 33.5 — 33.5 33.5 Total revenues 1,101.7 2,089.4 226.8 50.0 2.4 52.4 3,470.3 Benefits, losses and expenses Policyholder benefits (2) 356.3 420.9 131.7 — (3.7 ) (3.7 ) 905.2 Amortization of deferred acquisition costs and value of business acquired 100.0 675.9 33.7 — — — 809.6 Underwriting, general and administrative expenses 464.2 835.4 30.0 160.4 3.2 163.6 1,493.2 Interest expense — — — 47.5 — 47.5 47.5 Total benefits, losses and expenses 920.5 1,932.2 195.4 207.9 (0.5 ) 207.4 3,255.5 Segment income before provision for income tax 181.2 157.2 31.4 (157.9 ) 2.9 (155.0 ) 214.8 Provision for income taxes 37.4 33.3 6.9 (36.5 ) 0.7 (35.8 ) 41.8 Segment income after tax 143.8 123.9 24.5 (121.4 ) 2.2 (119.2 ) 173.0 Less: Preferred stock dividends — — — (4.8 ) — (4.8 ) (4.8 ) Net income attributable to common stockholders $ 143.8 $ 123.9 $ 24.5 $ (126.2 ) $ 2.2 $ (124.0 ) $ 168.2 Six Months Ended June 30, 2017 Total Corporate and Other Global Housing Global Lifestyle Global Preneed Corporate and Other Health Total Consolidated Revenues Net earned premiums $ 878.8 $ 1,251.8 $ 29.8 $ — $ 5.2 $ 5.2 $ 2,165.6 Fees and other income 203.1 389.1 60.7 11.8 2.4 14.2 667.1 Net investment income 36.0 52.9 129.2 19.4 4.8 24.2 242.3 Net realized gains on investments — — — 16.6 — 16.6 16.6 Amortization of deferred gains on disposal of businesses (1) — — — 60.4 — 60.4 60.4 Total revenues 1,117.9 1,693.8 219.7 108.2 12.4 120.6 3,152.0 Benefits, losses and expenses Policyholder benefits (2) 351.5 326.7 128.1 — (31.9 ) (31.9 ) 774.4 Amortization of deferred acquisition costs and value of business acquired 97.7 534.6 28.9 — — — 661.2 Underwriting, general and 488.2 695.3 29.2 57.5 27.4 84.9 1,297.6 Interest expense — — — 25.0 — 25.0 25.0 Total benefits, losses and expenses 937.4 1,556.6 186.2 82.5 (4.5 ) 78.0 2,758.2 Segment income before provision for income tax 180.5 137.2 33.5 25.7 16.9 42.6 393.8 Provision for income taxes 62.4 44.6 10.8 6.5 5.5 12.0 129.8 Segment income after tax $ 118.1 $ 92.6 $ 22.7 $ 19.2 $ 11.4 $ 30.6 $ 264.0 (1) The three months ended June 30, 2018 and 2017 include $12.7 million and $20.6 million , respectively, and the six months ended June 30, 2018 and 2017 include $29.0 million and $54.8 million , respectively, related to the amortization of deferred gains related to the 2016 sale of AEB. The remaining AEB unamortized deferred gain as of June 30, 2018 was $34.7 million . (2) The presentation of Assurant Health policyholder benefits includes the impact of the total current period net utilization of premium deficiency reserves for claim costs and claim adjustment expenses included in policyholder benefits, as well as maintenance costs, which are included within underwriting, general and administrative expenses. For the three months ended June 30, 2018 and 2017, the premium deficiency reserve liability decreased $0.7 million and $9.2 million , respectively, through an offset to policyholder benefit expense. For the six months ended June 30, 2018 and 2017, the premium deficiency reserve liability decreased $0.8 million and $21.9 million

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2018
Investments [Abstract]
Amortized Cost, Gross Unrealized Gains and Losses, Fair Value and OTTI	The investment category and duration of the Company’s gross unrealized losses on fixed maturity securities as of June 30, 2018 and December 31, 2017 were as follows: June 30, 2018 Less than 12 months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: U.S. government and government agencies and authorities $ 112.7 $ (1.5 ) $ 35.9 $ (0.6 ) $ 148.6 $ (2.1 ) States, municipalities and political subdivisions 150.8 (0.9 ) 3.3 (0.2 ) 154.1 (1.1 ) Foreign governments 296.8 (1.4 ) 6.5 (0.2 ) 303.3 (1.6 ) Asset-backed 225.4 (0.7 ) — — 225.4 (0.7 ) Commercial mortgage-backed 181.1 (1.7 ) 12.0 (1.1 ) 193.1 (2.8 ) Residential mortgage-backed 677.9 (12.6 ) 161.1 (8.8 ) 839.0 (21.4 ) U.S. corporate 2,037.9 (40.9 ) 49.5 (2.8 ) 2,087.4 (43.7 ) Foreign corporate 760.7 (10.1 ) 63.6 (1.8 ) 824.3 (11.9 ) Total fixed maturity securities $ 4,443.3 $ (69.8 ) $ 331.9 $ (15.5 ) $ 4,775.2 $ (85.3 ) December 31, 2017 Less than 12 months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fixed maturity securities: U.S. government and government agencies and authorities $ 104.2 $ (0.7 ) $ 43.3 $ (0.5 ) $ 147.5 $ (1.2 ) States, municipalities and political subdivisions — — 2.4 (0.1 ) 2.4 (0.1 ) Foreign governments 24.4 (0.2 ) 0.8 (0.1 ) 25.2 (0.3 ) Asset-backed 27.6 (0.1 ) — — 27.6 (0.1 ) Commercial mortgage-backed — — 12.4 (0.7 ) 12.4 (0.7 ) Residential mortgage-backed 217.3 (2.4 ) 162.9 (4.9 ) 380.2 (7.3 ) U.S. corporate 562.8 (4.5 ) 30.0 (0.5 ) 592.8 (5.0 ) Foreign corporate 266.7 (3.5 ) 19.0 (0.5 ) 285.7 (4.0 ) Total fixed maturity securities $ 1,203.0 $ (11.4 ) $ 270.8 $ (7.3 ) $ 1,473.8 $ (18.7 ) Equity securities: Non-redeemable preferred stock $ 13.8 $ (0.2 ) $ 8.7 $ (0.3 ) $ 22.5 $ (0.5 ) June 30, 2018 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value OTTI in AOCI (a) Fixed maturity securities: U.S. government and government agencies and authorities $ 184.1 $ 2.6 $ (2.1 ) $ 184.6 $ — States, municipalities and political subdivisions 461.6 17.9 (1.1 ) 478.4 — Foreign governments 858.4 62.8 (1.6 ) 919.6 — Asset-backed 494.7 1.2 (0.7 ) 495.2 — Commercial mortgage-backed 256.4 0.3 (2.8 ) 253.9 — Residential mortgage-backed 1,241.4 16.8 (21.4 ) 1,236.8 5.6 U.S. corporate 5,198.1 365.8 (43.7 ) 5,520.2 15.8 Foreign corporate 2,082.3 138.4 (11.9 ) 2,208.8 — Total fixed maturity securities $ 10,777.0 $ 605.8 $ (85.3 ) $ 11,297.5 $ 21.4 December 31, 2017 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value OTTI in AOCI (a) Fixed maturity securities: U.S. government and government agencies and authorities $ 180.6 $ 3.2 $ (1.2 ) $ 182.6 $ — States, municipalities and political subdivisions 302.3 24.0 (0.1 ) 326.2 — Foreign governments 524.8 72.3 (0.3 ) 596.8 — Asset-backed 188.4 1.9 (0.1 ) 190.2 1.0 Commercial mortgage-backed 38.6 0.2 (0.7 ) 38.1 — Residential mortgage-backed 1,084.2 32.5 (7.3 ) 1,109.4 9.2 U.S. corporate 4,774.2 602.1 (5.0 ) 5,371.3 17.4 Foreign corporate 1,663.4 188.6 (4.0 ) 1,848.0 — Total fixed maturity securities $ 8,756.5 $ 924.8 $ (18.7 ) $ 9,662.6 $ 27.6 Equity securities: Common stocks $ 9.3 $ 8.4 $ — $ 17.7 $ — Non-redeemable preferred stocks 307.0 43.8 (0.5 ) 350.3 — Total equity securities $ 316.3 $ 52.2 $ (0.5 ) $ 368.0 $ — (a)
Amortized Cost and Fair Value of Fixed Maturity Securities by Contractual Maturity	The cost or amortized cost and fair value of fixed maturity securities as of June 30, 2018 by contractual maturity are shown below. Actual maturities may differ from contractual maturities because issuers of the securities may have the right to call or prepay obligations with or without call or prepayment penalties. Cost or Amortized Cost Fair Value Due in one year or less $ 320.5 $ 322.1 Due after one year through five years 2,276.5 2,294.7 Due after five years through ten years 2,314.2 2,338.8 Due after ten years 3,873.3 4,356.0 Total 8,784.5 9,311.6 Asset-backed 494.7 495.2 Commercial mortgage-backed 256.4 253.9 Residential mortgage-backed 1,241.4 1,236.8 Total $ 10,777.0 $ 11,297.5
Net Realized Gains (Losses), Including Other-Than-Temporary Impairments	The following table sets forth the net realized gains (losses), including OTTI, recognized in the statement of operations: Three Months Ended Six Months Ended 2018 2017 2018 2017 Net realized gains (losses) on investments: Fixed maturity securities $ (7.6 ) $ 11.9 $ (10.2 ) $ 14.5 Equity securities (1) (5.9 ) 1.5 (3.7 ) 3.8 Other investments 1.2 (0.1 ) 2.5 (1.2 ) Consolidated investment entities (2) 0.9 — 0.5 — Total net realized gains (losses) on investments (11.4 ) 13.3 (10.9 ) 17.1 Net realized losses related to other-than-temporary impairments: Fixed maturity securities — — — (0.4 ) Other investments — (0.1 ) — (0.1 ) Total net realized losses related to other-than- temporary impairments — (0.1 ) — (0.5 ) Total net realized gains (losses) $ (11.4 ) $ 13.2 $ (10.9 ) $ 16.6 (1) Six months ended June 30, 2018 includes a $7.8 million gain on one equity investment holding accounted for under the measurement alternative based on an observable market event where the implied value increased based on a new investment. Equity investments accounted for under the measurement alternative are included within Other investments on the consolidated balance sheet. (2)
Unrealized Gains on Equity Securities	The following table sets forth the portion of unrealized gains related to equity securities during the three and six months ended June 30, 2018: Three Months Ended Six Months Ended 2018 2018 Net losses recognized on equity securities $ (5.9 ) $ (3.7 ) Less: Net realized gains related to sales of equity securities 2.3 3.7 Total unrealized losses on equity securities held (1) $ (8.2 ) $ (7.4 ) (1) Net gains for 2018 are required to be reported through the income statement in accordance with the 2018 accounting guidance on financial instruments. Net unrealized gains of $9.0 million and $17.4 million

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2018
Variable Interest Entities [Abstract]
Balances of assets and liabilities held by consolidated investment entities at fair value	The following table presents the balances of assets and liabilities held by consolidated investment entities measured at fair value on a recurring basis. Amounts presented are as of June 30, 2018 and December 31, 2017, respectively. June 30, 2018 Total Level 1 Level 2 Level 3 Financial Assets Investments: Cash and cash equivalents $ 35.0 $ 35.0 (1) $ — $ — Corporate debt securities 1,098.2 — 1,098.2 — Real estate fund 102.5 — — 102.5 Total financial assets $ 1,235.7 $ 35.0 $ 1,098.2 $ 102.5 Financial Liabilities Collateralized loan obligation notes $ 941.3 $ — $ 941.3 $ — Total financial liabilities $ 941.3 $ — $ 941.3 $ — December 31, 2017 Total Level 1 Level 2 Level 3 Financial Assets Investments: Cash and cash equivalents $ 54.5 $ 54.5 (1) $ — $ — Corporate debt securities 570.3 — 570.3 — Real estate fund 84.7 — — 84.7 Total financial assets $ 709.5 $ 54.5 $ 570.3 $ 84.7 Financial Liabilities Collateralized loan obligation notes $ 450.7 $ — $ 450.7 $ — Total financial liabilities $ 450.7 $ — $ 450.7 $ — (1) June 30, 2018 Total Level 1 Level 2 Level 3 Financial Assets Fixed maturity securities: U.S. government and government agencies and authorities $ 184.6 $ — $ 184.6 $ — State, municipalities and political subdivisions 478.4 — 478.4 — Foreign governments 919.6 0.6 919.0 — Asset-backed 495.2 — 450.1 45.1 Commercial mortgage-backed 253.9 — 194.0 59.9 Residential mortgage-backed 1,236.8 — 1,236.8 — U.S. corporate 5,520.2 — 5,484.8 35.4 Foreign corporate 2,208.8 — 2,158.2 50.6 Equity securities: Mutual funds 46.0 46.0 — — Common stocks 16.6 15.9 0.7 — Non-redeemable preferred stocks 323.2 — 321.0 2.2 Short-term investments 343.6 91.0 (2) 252.6 — Other investments 243.5 74.0 (1) 168.0 (3) 1.5 (4) Cash equivalents 637.5 469.0 (2) 168.5 (3) — Other assets 3.1 — 1.5 1.6 (5) Assets held in separate accounts 1,824.0 1,674.0 (1) 150.0 (3) — Total financial assets $ 14,735.0 $ 2,370.5 $ 12,168.2 $ 196.3 Financial Liabilities Other liabilities $ 119.4 $ 74.0 (1) $ — (5) $ 45.4 (6) Liabilities related to separate accounts 1,824.0 1,674.0 (1) 150.0 (3) — Total financial liabilities $ 1,943.4 $ 1,748.0 $ 150.0 $ 45.4 December 31, 2017 Total Level 1 Level 2 Level 3 Financial Assets Fixed maturity securities: U.S. government and government agencies and authorities $ 182.6 $ — $ 182.6 $ — State, municipalities and political subdivisions 326.2 — 326.2 — Foreign governments 596.8 1.0 595.8 — Asset-backed 190.2 — 150.8 39.4 Commercial mortgage-backed 38.1 — 9.5 28.6 Residential mortgage-backed 1,109.4 — 1,109.4 — U.S. corporate 5,371.3 — 5,350.2 21.1 Foreign corporate 1,848.0 — 1,802.7 45.3 Equity securities: Common stocks 17.7 17.0 0.7 — Non-redeemable preferred stocks 350.3 — 348.1 2.2 Short-term investments 284.1 141.6 (2) 142.5 — Other investments 253.9 71.2 (1) 172.7 (3) 10.0 (4) Cash equivalents 544.9 519.1 (2) 25.8 (3) — Other assets 2.1 — — 2.1 (5) Assets held in separate accounts 1,800.6 1,635.2 (1) 165.4 (3) — Total financial assets $ 12,916.2 $ 2,385.1 $ 10,382.4 $ 148.7 Financial Liabilities Other liabilities $ 128.7 $ 71.2 (1) $ 1.0 (5) $ 56.5 (6) Liabilities related to separate accounts 1,800.6 1,635.2 (1) 165.4 (3) — Total financial liabilities $ 1,929.3 $ 1,706.4 $ 166.4 $ 56.5 (1) Primarily includes mutual funds and related obligations. (2) Primarily includes money market funds. (3) Primarily includes fixed maturity securities and related obligations. (4) Primarily includes fixed maturity securities and other derivatives. (5) Primarily includes other derivative assets and liabilities. (6) Primarily includes contingent consideration liabilities related to business combinations and other derivatives. (7) Primarily includes fixed maturity securities and certificates of deposit.
Schedule of carrying values of level 3 assets	The following table summarizes the change in balance sheet carrying value associated with Level 3 assets held by consolidated investment entities measured at fair value during the three and six months ended June 30, 2018: Three Months Ended June 30, 2018 Six Months Ended June 30, 2018 Balance, beginning of period $ 86.8 $ 84.7 Purchases 23.0 23.0 Sales (6.8 ) (6.8 ) Total (loss) income included in earnings (0.5 ) 1.6 Balance, end of period $ 102.5 $ 102.5

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Hierarchy for Assets and Liabilities	The following table presents the balances of assets and liabilities held by consolidated investment entities measured at fair value on a recurring basis. Amounts presented are as of June 30, 2018 and December 31, 2017, respectively. June 30, 2018 Total Level 1 Level 2 Level 3 Financial Assets Investments: Cash and cash equivalents $ 35.0 $ 35.0 (1) $ — $ — Corporate debt securities 1,098.2 — 1,098.2 — Real estate fund 102.5 — — 102.5 Total financial assets $ 1,235.7 $ 35.0 $ 1,098.2 $ 102.5 Financial Liabilities Collateralized loan obligation notes $ 941.3 $ — $ 941.3 $ — Total financial liabilities $ 941.3 $ — $ 941.3 $ — December 31, 2017 Total Level 1 Level 2 Level 3 Financial Assets Investments: Cash and cash equivalents $ 54.5 $ 54.5 (1) $ — $ — Corporate debt securities 570.3 — 570.3 — Real estate fund 84.7 — — 84.7 Total financial assets $ 709.5 $ 54.5 $ 570.3 $ 84.7 Financial Liabilities Collateralized loan obligation notes $ 450.7 $ — $ 450.7 $ — Total financial liabilities $ 450.7 $ — $ 450.7 $ — (1) June 30, 2018 Total Level 1 Level 2 Level 3 Financial Assets Fixed maturity securities: U.S. government and government agencies and authorities $ 184.6 $ — $ 184.6 $ — State, municipalities and political subdivisions 478.4 — 478.4 — Foreign governments 919.6 0.6 919.0 — Asset-backed 495.2 — 450.1 45.1 Commercial mortgage-backed 253.9 — 194.0 59.9 Residential mortgage-backed 1,236.8 — 1,236.8 — U.S. corporate 5,520.2 — 5,484.8 35.4 Foreign corporate 2,208.8 — 2,158.2 50.6 Equity securities: Mutual funds 46.0 46.0 — — Common stocks 16.6 15.9 0.7 — Non-redeemable preferred stocks 323.2 — 321.0 2.2 Short-term investments 343.6 91.0 (2) 252.6 — Other investments 243.5 74.0 (1) 168.0 (3) 1.5 (4) Cash equivalents 637.5 469.0 (2) 168.5 (3) — Other assets 3.1 — 1.5 1.6 (5) Assets held in separate accounts 1,824.0 1,674.0 (1) 150.0 (3) — Total financial assets $ 14,735.0 $ 2,370.5 $ 12,168.2 $ 196.3 Financial Liabilities Other liabilities $ 119.4 $ 74.0 (1) $ — (5) $ 45.4 (6) Liabilities related to separate accounts 1,824.0 1,674.0 (1) 150.0 (3) — Total financial liabilities $ 1,943.4 $ 1,748.0 $ 150.0 $ 45.4 December 31, 2017 Total Level 1 Level 2 Level 3 Financial Assets Fixed maturity securities: U.S. government and government agencies and authorities $ 182.6 $ — $ 182.6 $ — State, municipalities and political subdivisions 326.2 — 326.2 — Foreign governments 596.8 1.0 595.8 — Asset-backed 190.2 — 150.8 39.4 Commercial mortgage-backed 38.1 — 9.5 28.6 Residential mortgage-backed 1,109.4 — 1,109.4 — U.S. corporate 5,371.3 — 5,350.2 21.1 Foreign corporate 1,848.0 — 1,802.7 45.3 Equity securities: Common stocks 17.7 17.0 0.7 — Non-redeemable preferred stocks 350.3 — 348.1 2.2 Short-term investments 284.1 141.6 (2) 142.5 — Other investments 253.9 71.2 (1) 172.7 (3) 10.0 (4) Cash equivalents 544.9 519.1 (2) 25.8 (3) — Other assets 2.1 — — 2.1 (5) Assets held in separate accounts 1,800.6 1,635.2 (1) 165.4 (3) — Total financial assets $ 12,916.2 $ 2,385.1 $ 10,382.4 $ 148.7 Financial Liabilities Other liabilities $ 128.7 $ 71.2 (1) $ 1.0 (5) $ 56.5 (6) Liabilities related to separate accounts 1,800.6 1,635.2 (1) 165.4 (3) — Total financial liabilities $ 1,929.3 $ 1,706.4 $ 166.4 $ 56.5 (1) Primarily includes mutual funds and related obligations. (2) Primarily includes money market funds. (3) Primarily includes fixed maturity securities and related obligations. (4) Primarily includes fixed maturity securities and other derivatives. (5) Primarily includes other derivative assets and liabilities. (6) Primarily includes contingent consideration liabilities related to business combinations and other derivatives. (7) Primarily includes fixed maturity securities and certificates of deposit.
Carrying Value and Fair Value of the Financial Instruments that are Not recognized or are Not Carried at Fair Value	The following tables disclose the carrying value, fair value amount and hierarchy level of the financial instruments that are not carried at fair value in the consolidated balance sheets: June 30, 2018 Fair Value Carrying Value Total Level 1 Level 2 Level 3 Financial Assets Commercial mortgage loans on real estate $ 720.1 $ 716.0 $ — $ — $ 716.0 Other investments 94.7 94.7 35.0 — 59.7 Other assets 45.0 45.0 — — 45.0 Total financial assets $ 859.8 $ 855.7 $ 35.0 $ — $ 820.7 Financial Liabilities Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal) (1) $ 608.4 $ 608.5 $ — $ — $ 608.5 Funds withheld under reinsurance 347.1 347.1 347.1 — — Debt 2,004.8 2,084.9 — 2,084.9 — Total financial liabilities $ 2,960.3 $ 3,040.5 $ 347.1 $ 2,084.9 $ 608.5 December 31, 2017 Fair Value Carrying Value Total Level 1 Level 2 Level 3 Financial Assets Commercial mortgage loans on real estate $ 670.2 $ 679.2 $ — $ — $ 679.2 Other investments 84.4 84.4 36.3 — 48.1 Total financial assets $ 754.6 $ 763.6 $ 36.3 $ — $ 727.3 Financial Liabilities Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal) (1) $ 634.3 $ 642.5 $ — $ — $ 642.5 Funds withheld under reinsurance 179.8 179.8 179.8 — — Debt 1,068.2 1,174.4 — 1,174.4 — Total financial liabilities $ 1,882.3 $ 1,996.7 $ 179.8 $ 1,174.4 $ 642.5 (1)

Reserves (Tables)

Reserves (Tables)	6 Months Ended
	Jun. 30, 2018
Insurance Loss Reserves [Abstract]
Roll Forward of Claims and Benefits Payable	The following table provides a roll forward of the Company’s beginning and ending claims and benefits payable balances. Claims and benefits payable is the liability for unpaid loss and loss adjustment expenses and is comprised of case and incurred but not reported ("IBNR") reserves. Since unpaid loss and loss adjustment expenses are estimates, the Company’s actual losses incurred may be more or less than the Company’s previously developed estimates, which is referred to as either unfavorable or favorable development, respectively. The best estimate of ultimate loss and loss adjustment expense is generally selected from a blend of methods that are applied consistently each period. There have been no significant changes in the methodologies and assumptions utilized in estimating the liability for unpaid loss and loss adjustment expenses for any of the periods presented. For the Six Months Ended June 30, 2018 2017 Claims and benefits payable, at beginning of period $ 3,782.2 $ 3,301.2 Less: Reinsurance ceded and other (3,193.3 ) (2,718.2 ) Net claims and benefits payable, at beginning of period 588.9 583.0 Acquired reserves as of Acquisition Date (1) 142.9 — Incurred losses and loss adjustment expenses related to: Current year 938.1 856.3 Prior years (30.6 ) (60.0 ) Total incurred losses and loss adjustment expenses 907.5 796.3 Paid losses and loss adjustment expenses related to: Current year 624.6 556.0 Prior years 336.4 262.8 Total paid losses and loss adjustment expenses 961.0 818.8 Net claims and benefits payable, at end of period 678.3 560.5 Plus: Reinsurance ceded and other 2,824.8 2,532.8 Claims and benefits payable, at end of period $ 3,503.1 $ 3,093.3 (1) Acquired reserves from TWG on May 31, 2018 (the Acquisition Date) include $423.5 million of gross claims and benefits payable and $280.6 million

Goodwill and Other Intangible37

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	A roll forward of goodwill by segment is provided below. Global Housing Global Lifestyle Global Preneed Consolidated Balance at December 31, 2017 (1) $ 386.7 $ 392.8 $ 138.2 $ 917.7 Acquisitions (2) — 1,463.8 — 1,463.8 Impairments (3) (8.1 ) — — (8.1 ) Foreign currency translation and other — (3.9 ) (0.3 ) (4.2 ) Balance at June 30, 2018 $ 378.6 $ 1,852.7 $ 137.9 $ 2,369.2 (1) Net of $1.26 billion of accumulated impairment losses. (2) Refer to Note 4 for additional information on the TWG acquisition. (3)
Schedule of Finite-Lived Intangible Assets	The following table shows the preliminary purchase price allocation to VOBA and Other intangible assets and the related estimated useful lives. Amount Estimated Useful Life VOBA $ 3,995.7 9 years Finite life: Distribution network 392.4 15 years Technology based intangibles 57.4 9 years Total finite life other intangible assets 449.8 Indefinite life: Licenses $ 11.6 Indefinite Total other intangible assets $ 461.4
Schedule of Indefinite-Lived Intangible Assets	The following table shows the preliminary purchase price allocation to VOBA and Other intangible assets and the related estimated useful lives. Amount Estimated Useful Life VOBA $ 3,995.7 9 years Finite life: Distribution network 392.4 15 years Technology based intangibles 57.4 9 years Total finite life other intangible assets 449.8 Indefinite life: Licenses $ 11.6 Indefinite Total other intangible assets $ 461.4
Finite-lived Intangible Assets Amortization Expense	At June 30, 2018, the estimated amortization of VOBA and Other intangible assets for the remainder of 2018, the next five years and thereafter is as follows: VOBA Other Intangible Assets (With Finite Lives) Related to TWG Acquisition Other Total Related to TWG Acquisition Other Total July 1 - December 31, 2018 $ 210.6 $ 3.5 $ 214.1 $ 7.3 $ 30.1 $ 37.4 2019 519.6 6.6 526.2 19.4 41.3 60.7 2020 632.2 6.3 638.5 27.6 35.4 63.0 2021 695.9 0.8 696.7 31.3 26.8 58.1 2022 759.4 0.7 760.1 35.0 17.3 52.3 2023 765.7 0.6 766.3 36.2 11.6 47.8 Thereafter 358.3 2.3 360.6 291.0 40.7 331.7 Total $ 3,941.7 $ 20.8 $ 3,962.5 $ 447.8 $ 203.2 $ 651.0

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Schedule of Credit Rating Agencies interest rates	The following table details the increase in interest rate over the issuance rate by rating with the impact equal to the sum of the number of basis points next to such rating for a maximum increase of 200 basis points over the issuance rate: Rating Agencies Rating Levels Moody's (1) S&P (1) Interest Rate Increase (2) 1 Ba1 BB+ 25 basis points 2 Ba2 BB 50 basis points 3 Ba3 BB- 75 basis points 4 B1 or below B+ or below 100 basis points (1) Including the equivalent ratings of any substitute rating agency. (2)

Accumulated Other Comprehensi39

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of Accumulated Other Comprehensive Income, Net of Tax	The following tables summarize those reclassification adjustments (net of taxes): Three Months Ended June 30, 2018 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at March 31, 2018 $ (272.3 ) $ 372.1 $ 21.1 $ 14.4 $ (83.6 ) $ 51.7 Change in accumulated other comprehensive (loss) income before reclassifications (83.1 ) (110.6 ) 0.5 (1.4 ) — (194.6 ) Amounts reclassified from accumulated other comprehensive (loss) income — 4.7 (0.7 ) — 1.0 5.0 Net current-period other comprehensive income (loss) (83.1 ) (105.9 ) (0.2 ) (1.4 ) 1.0 (189.6 ) Balance at June 30, 2018 $ (355.4 ) $ 266.2 $ 20.9 $ 13.0 $ (82.6 ) $ (137.9 ) Three Months Ended June 30, 2017 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at March 31, 2017 $ (300.3 ) $ 491.7 $ — $ 20.3 $ (63.4 ) $ 148.3 Change in accumulated other comprehensive (loss) income before reclassifications 15.7 80.9 — (1.5 ) — 95.1 Amounts reclassified from accumulated other comprehensive (loss) income — (7.0 ) — — 0.5 (6.5 ) Net current-period other comprehensive (loss) income 15.7 73.9 — (1.5 ) 0.5 88.6 Balance at June 30, 2017 $ (284.6 ) $ 565.6 $ — $ 18.8 $ (62.9 ) $ 236.9 Six Months Ended June 30, 2018 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at December 31, 2017 $ (281.5 ) $ 581.2 $ — $ 17.9 $ (83.6 ) $ 234.0 Change in accumulated other comprehensive (loss) income before reclassifications (73.9 ) (288.5 ) 21.6 (4.9 ) — (345.7 ) Amounts reclassified from accumulated other comprehensive (loss) income — 7.4 (0.7 ) — 1.0 7.7 Net current-period other comprehensive income (loss) (73.9 ) (281.1 ) 20.9 (4.9 ) 1.0 (338.0 ) Cumulative effect of change in accounting principles (1) — (33.9 ) — — — (33.9 ) Balance at June 30, 2018 $ (355.4 ) $ 266.2 $ 20.9 $ 13.0 $ (82.6 ) $ (137.9 ) Six Months Ended June 30, 2017 Foreign currency translation adjustment Net unrealized gains on securities Net unrealized gains on derivative transactions OTTI Unamortized net (losses) on Pension Plans Accumulated other comprehensive income Balance at December 31, 2016 $ (322.1 ) $ 459.3 $ — $ 20.6 $ (63.2 ) $ 94.6 Change in accumulated other comprehensive (loss) income before reclassifications 37.5 117.1 — (1.8 ) — 152.8 Amounts reclassified from accumulated other comprehensive (loss) income — (10.8 ) — — 0.3 (10.5 ) Net current-period other comprehensive (loss) income 37.5 106.3 — (1.8 ) 0.3 142.3 Balance at June 30, 2017 $ (284.6 ) $ 565.6 $ — $ 18.8 $ (62.9 ) $ 236.9 (1) See Note 3 for additional information.
Reclassification out of Accumulated Other Comprehensive Income	The following tables summarize the reclassifications out of accumulated other comprehensive income for the three and six months ended June 30, 2018 and 2017: Details about accumulated other comprehensive income components Amount reclassified from accumulated other comprehensive income Affected line item in the statement where net income is presented Three Months Ended June 30, 2018 2017 Net unrealized gains on securities $ 6.0 $ (10.8 ) Net realized gains on investments, excluding other-than-temporary impairment losses (1.3 ) 3.8 Provision for income taxes $ 4.7 $ (7.0 ) Net of tax Unrealized gains on derivative transactions $ (0.9 ) $ — Interest Expense 0.2 — Provision for income taxes $ (0.7 ) $ — Net of tax Amortization of pension and postretirement unrecognized net periodic benefit cost: Amortization of net loss $ 1.2 $ 0.8 (1) (0.2 ) (0.3 ) Provision for income taxes $ 1.0 $ 0.5 Net of tax Total reclassifications for the period $ 5.0 $ (6.5 ) Net of tax Details about accumulated other comprehensive income components Amount reclassified from accumulated other comprehensive income Affected line item in the statement where net income is presented Six Months Ended June 30, 2018 2017 Net unrealized gains on securities $ 9.4 $ (16.7 ) Net realized gains on investments, excluding other-than-temporary impairment losses (2.0 ) 5.9 Provision for income taxes $ 7.4 $ (10.8 ) Net of tax Unrealized gains on derivative transactions $ (0.9 ) $ — Interest Expense 0.2 — Provision for income taxes $ (0.7 ) $ — Net of tax Amortization of pension and postretirement unrecognized net periodic benefit cost: Settlement gain $ — $ (0.6 ) Settlement gain Amortization of net loss 1.2 1.1 (1) 1.2 0.5 Total before tax (0.2 ) (0.2 ) Provision for income taxes $ 1.0 $ 0.3 Net of tax Total reclassifications for the period $ 7.7 $ (10.5 ) Net of tax (1)

Stock Based Compensation (Table

Stock Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Based Compensation Activity	The following table shows a summary of PSU activity during the three and six months ended June 30, 2018 and 2017: Three Months Ended Six Months Ended 2018 2017 2018 2017 PSU compensation expense $ 3.1 $ 3.2 $ 7.3 $ 0.1 Income tax benefit (0.4 ) (1.1 ) (1.3 ) — PSU compensation expense, net of tax $ 2.7 $ 2.1 $ 6.0 $ 0.1 PSUs granted — — — 237,623 Weighted average grant date fair value per unit $ — $ — $ — $ 112.32 Total fair value of vested PSUs $ 25.6 $ 29.4 $ 25.6 $ 29.4 Three Months Ended Six Months Ended 2018 2017 2018 2017 RSU compensation expense $ 8.7 $ 6.1 $ 13.8 $ 10.8 Income tax benefit (1.5 ) (2.1 ) (2.3 ) (3.8 ) RSU compensation expense, net of tax $ 7.2 $ 4.0 $ 11.5 $ 7.0 RSUs granted 32,330 31,554 421,829 205,199 Weighted average grant date fair value per unit $ 89.56 $ 99.74 $ 90.64 $ 99.17 Total fair value of vested RSUs $ 2.6 $ 3.5 $ 18.8 $ 23.9

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Net Income, Weighted Average Common Shares Used in Calculating Basic Earnings Per Common Share and Diluted EPS	The following table presents net income, the weighted average common shares used in calculating basic earnings per common share (“EPS”) and those used in calculating diluted EPS for each period presented below. Diluted EPS reflects the incremental common shares from: (1) shares issuable upon vesting of PSUs and ESPP using the treasury stock method; and (2) shares issuable upon conversion of the MCPS using the if-converted method. Refer to Note 14 - Stock Based Compensation and Note 15 - Equity Transactions for further information regarding potential common share issuances. The outstanding RSUs have non-forfeitable rights to dividend equivalents and are therefore included in calculating basic and diluted EPS under the two-class method. Three Months Ended Six Months Ended 2018 2017 2018 2017 Numerator Net income $ 67.0 $ 120.2 $ 173.0 $ 264.0 Less: Preferred stock dividends (4.8 ) — (4.8 ) — Net income attributable to common stockholders 62.2 120.2 168.2 264.0 Less: Common stock dividends paid (30.9 ) (30.3 ) (60.6 ) (60.0 ) Undistributed earnings $ 31.3 $ 89.9 $ 107.6 $ 204.0 Denominator Weighted average shares outstanding used in basic earnings per share 57,060,313 55,230,367 55,125,584 55,713,172 Incremental common shares from: PSUs 163,596 239,400 217,455 321,849 ESPP 40,499 40,131 40,499 40,131 MCPS — — 1,889,890 — Weighted average shares used in diluted earnings per share calculations 57,264,408 55,509,898 57,273,428 56,075,152 Earnings per common share - Basic Distributed earnings $ 0.54 $ 0.55 $ 1.10 $ 1.08 Undistributed earnings 0.55 1.63 1.95 3.66 Net income attributable to common stockholders $ 1.09 $ 2.18 $ 3.05 $ 4.74 Earnings per common share - Diluted Distributed earnings $ 0.54 $ 0.54 $ 1.06 $ 1.07 Undistributed earnings 0.55 1.62 1.96 3.64 Net income attributable to common stockholders $ 1.09 $ 2.16 $ 3.02 $ 4.71

Retirement and Other Employee42

Retirement and Other Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2018
Defined Benefit Plan [Abstract]
Components of Net Periodic Benefit Cost	The components of net periodic benefit cost for the Company’s qualified pension benefits plan, nonqualified pension benefits plan and retirement health benefits plan for the three and six months ended June 30, 2018 and 2017 were as follows: Qualified Pension Benefits Unfunded Nonqualified Pension Benefits Retirement Health Benefits For the Three Months Ended June 30, For the Three Months Ended June 30, For the Three Months Ended June 30, 2018 2017 Plan 1 2017 Plan 2 2018 2017 2018 2017 Interest cost 5.8 2.9 3.1 0.7 0.7 0.9 0.8 Expected return on plan assets (9.1 ) (6.1 ) (6.8 ) — — (0.6 ) (0.7 ) Amortization of net loss 0.2 — 0.3 0.3 0.3 — — Net periodic benefit cost $ (3.1 ) $ (3.2 ) $ (3.4 ) $ 1.0 $ 1.0 $ 0.3 $ 0.1 Qualified Pension Benefits Unfunded Nonqualified Pension Benefits Retirement Health Benefits For the Six Months Ended June 30, For the Six Months Ended June 30, For the Six Months Ended June 30, 2018 2017 Plan 1 2017 Plan 2 2018 2017 2018 2017 Interest cost $ 11.6 $ 5.8 $ 6.2 $ 1.4 $ 1.5 $ 1.7 $ 1.7 Expected return on plan assets (18.2 ) (12.2 ) (13.6 ) — — (1.1 ) (1.5 ) Amortization of net loss 0.4 — 0.6 0.8 0.6 — — Curtailment/settlement gain — — — — (0.7 ) — — Net periodic benefit cost $ (6.2 ) $ (6.4 ) $ (6.8 ) $ 2.2 $ 1.4 $ 0.6 $ 0.2

Recent Accounting Pronounceme43

Recent Accounting Pronouncements (Additional Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2018	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percentage of revenue from contract with customers	20.00%
Accounts payable and other liabilities	$ 2,046.3	$ 2,610.7
Other assets	387.1	623.7
Retained earnings	5,697.3	5,846.3
Tax receivable	$ 126.3	$ 54.3
Difference between Revenue Guidance in effect before and after Topic 606 | ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings			$ 33.9
Difference between Revenue Guidance in effect before and after Topic 606 | ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts payable and other liabilities			(10)
Other assets			(0.3)
Retained earnings			7.5
Tax receivable			$ 2.2

Acquisitions (Details)

Acquisitions (Details) - TWG Holdings Limited - USD ($) $ in Millions	May 31, 2018	Jun. 30, 2018
Business Acquisition [Line Items]
Total acquisition consideration	$ 2,466.3
Aggregate cash consideration	894.9
Repayment of pre-existing TWG debt	595.9
Share issuance consideration	$ 975.5
Common stock shares issued to TWG equityholders	10,399,862
Percentage of outstanding common stock acquired		16.50%

Acquisitions (Purchase Consider

Acquisitions (Purchase Consideration) (Details) - TWG Holdings Limited $ / shares in Units, $ in Millions	May 31, 2018USD ($)$ / sharesshares
Business Acquisition [Line Items]
Common stock shares issued to TWG equityholders | shares	10,399,862
Volume weighted average common share price of Assurant, Inc. on May 31, 2018 | $ / shares	$ 93.80
Share issuance consideration	$ 975.5
Aggregate cash consideration	894.9
Repayment of pre-existing TWG debt	595.9
Total acquisition consideration	$ 2,466.3

Acquisitions (Fair Value of Net

Acquisitions (Fair Value of Net Assets Acquired and Liabilities Assumed) (Details) - USD ($)	May 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill		$ 2,369,200,000	$ 917,700,000
TWG Holdings Limited
Business Acquisition [Line Items]
Fixed maturity securities available for sale	$ 2,359,300,000
Equity securities	49,400,000
Short-term investments	174,500,000
Other investments	104,200,000
Cash and cash equivalents	277,300,000
Premiums and accounts receivable, net	275,200,000
Reinsurance recoverables	1,917,500,000
Accrued investment income	31,600,000
Property and equipment	15,400,000
Value of business acquired	3,995,700,000
Other intangible assets	461,400,000
Other assets	195,500,000
Unearned premiums and contract fees	(7,250,700,000)
Claims and benefits payable	(423,500,000)
Reinsurance balances payable	(186,100,000)
Funds held under reinsurance	(200,800,000)
Accounts payable and other liabilities	(791,600,000)
Non-controlling interest	(1,800,000)
Total identifiable net assets acquired	1,002,500,000
Goodwill	1,463,800,000
Total acquisition consideration	2,466,300,000
Tax-deductible goodwill	0
Amortizable intangible assets	449,800,000
Indefinite-lived intangible assets	$ 11,600,000
Minimum | TWG Holdings Limited
Business Acquisition [Line Items]
Estimated useful lives (in years)	3 years
Maximum | TWG Holdings Limited
Business Acquisition [Line Items]
Estimated useful lives (in years)	15 years

Acquisitions Acquisitions (Acqu

Acquisitions Acquisitions (Acquisition-related Costs) (Details) - TWG Holdings Limited - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Business Acquisition [Line Items]
Transaction costs, incurred to date		$ 39.3
Integration costs, incurred to date		13.5
Underwriting, general and administrative expense
Business Acquisition [Line Items]
Transaction costs	$ 24.8	30
Integration costs	$ 10.5	$ 12.8

Acquisitions (Supplemental Pro

Acquisitions (Supplemental Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Total revenues			$ 4,519.1	$ 4,197.7
Net income			$ 244	$ 282.5
Basic earnings per share (in dollars per share)			$ 3.68	$ 4.13
Diluted earnings per share (in dollars per share)			$ 3.64	$ 4.07
Total Corporate and Other
Business Acquisition [Line Items]
Provision (benefit) for income taxes	$ 5.7		$ 5.7
Global Lifestyle
Business Acquisition [Line Items]
Provision (benefit) for income taxes		$ 3.9	$ 3.9
TWG Holdings Limited
Business Acquisition [Line Items]
Total revenues	210.3
Net income	9.3
TWG Holdings Limited | Global Lifestyle
Business Acquisition [Line Items]
Total revenues	211.9
Net income	9.4
TWG Holdings Limited | Corporate & Other
Business Acquisition [Line Items]
Total revenues	(1.6)
Net income	$ (0.1)
Acquisition-related Costs
Business Acquisition [Line Items]
Pro forma net income, nonrecurring transaction and integration costs, net of taxes				$ 19.4

Acquisitions (Prior Year Acquis

Acquisitions (Prior Year Acquisition) (Details) - USD ($)	Feb. 01, 2017	Jun. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Liabilities recorded in acquisition	$ 10,400,000
Goodwill		$ 2,369,200,000	$ 917,700,000
Green Tree Insurance Agency, Inc.
Business Acquisition [Line Items]
Acquisition percentage	100.00%
Aggregate cash consideration	$ 125,000,000
Earn-out (up to)	25,000,000
Goodwill	65,800,000
Tax-deductible goodwill	0
Agency relationship and renewal rights | Green Tree Insurance Agency, Inc.
Business Acquisition [Line Items]
Amortizable intangible assets	$ 69,600,000
Agency relationship and renewal rights | Minimum | Green Tree Insurance Agency, Inc.
Business Acquisition [Line Items]
Amortizable period	7 years
Agency relationship and renewal rights | Maximum | Green Tree Insurance Agency, Inc.
Business Acquisition [Line Items]
Amortizable period	16 years

Segment Information (Financial

Segment Information (Financial Information by Segment) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)reportable_segment	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | reportable_segment			4
Revenues
Net earned premiums	$ 1,338.3	$ 1,115.3	$ 2,463.2	$ 2,165.6
Fees and other income	354.2	326.9	718.7	667.1
Net investment income	135.6	121.7	265.8	242.3
Net realized gains on investments	(11.4)	13.2	(10.9)	16.6
Amortization of deferred gains and gains on disposal of businesses	15	23.4	33.5	60.4
Total revenues	1,831.7	1,600.5	3,470.3	3,152
Benefits, losses and expenses
Policyholder benefits	490.6	416.4	905.2	774.4
Amortization of deferred acquisition costs and value of business acquired	463.2	346.7	809.6	661.2
Underwriting, general and administrative expenses	773.6	646.3	1,493.2	1,297.6
Interest expense	26	12.4	47.5	25
Total benefits, losses and expenses	1,753.4	1,421.8	3,255.5	2,758.2
Segment income before provision for income tax	78.3	178.7	214.8	393.8
Provision (benefit) for income taxes	11.3	58.5	41.8	129.8
Net income	67	120.2	173	264
Less: Preferred stock dividends	(4.8)	0	(4.8)	0
Net income attributable to common stockholders	62.2	120.2	168.2	264
Segment assets	42,361.3		42,361.3		$ 31,843
Increase (decrease) in premium deficiency reserve liability			907.5	796.3
AEB | Disposal group, not discontinued operations
Benefits, losses and expenses
Amortization of deferred gains	12.7	20.6	29	54.8
Deferred gain on disposal	34.7		34.7
Health
Benefits, losses and expenses
Increase (decrease) in premium deficiency reserve liability	(0.7)	(9.2)	(0.8)	(21.9)
Global Housing
Revenues
Net earned premiums	449.7	442.4	886.1	878.8
Fees and other income	92.8	107.8	179.5	203.1
Net investment income	15.9	16.8	36.1	36
Net realized gains on investments	0	0	0	0
Amortization of deferred gains and gains on disposal of businesses	0	0	0	0
Total revenues	558.4	567	1,101.7	1,117.9
Benefits, losses and expenses
Policyholder benefits	187.2	188.2	356.3	351.5
Amortization of deferred acquisition costs and value of business acquired	50.4	46.8	100	97.7
Underwriting, general and administrative expenses	229.3	247.5	464.2	488.2
Interest expense	0	0	0	0
Total benefits, losses and expenses	466.9	482.5	920.5	937.4
Segment income before provision for income tax	91.5	84.5	181.2	180.5
Provision (benefit) for income taxes	18.9	28.3	37.4	62.4
Net income	72.6	56.2	143.8	118.1
Less: Preferred stock dividends	0		0
Net income attributable to common stockholders	72.6		143.8
Segment assets	3,930.1		3,930.1
Global Lifestyle
Revenues
Net earned premiums	874.3	656	1,547.9	1,251.8
Fees and other income	227.9	180	472.8	389.1
Net investment income	36.6	26.4	68.7	52.9
Net realized gains on investments	0	0	0	0
Amortization of deferred gains and gains on disposal of businesses	0	0	0	0
Total revenues	1,138.8	862.4	2,089.4	1,693.8
Benefits, losses and expenses
Policyholder benefits	239.3	178.1	420.9	326.7
Amortization of deferred acquisition costs and value of business acquired	395.6	283.6	675.9	534.6
Underwriting, general and administrative expenses	419.6	340.6	835.4	695.3
Interest expense	0	0	0	0
Total benefits, losses and expenses	1,054.5	802.3	1,932.2	1,556.6
Segment income before provision for income tax	84.3	60.1	157.2	137.2
Provision (benefit) for income taxes	16.2	19.9	33.3	44.6
Net income	68.1	40.2	123.9	92.6
Less: Preferred stock dividends	0		0
Net income attributable to common stockholders	68.1		123.9
Segment assets	20,561.5		20,561.5
Global Preneed
Revenues
Net earned premiums	14.2	15.2	28.8	29.8
Fees and other income	32.7	31.1	64.3	60.7
Net investment income	67.9	65	133.7	129.2
Net realized gains on investments	0	0	0	0
Amortization of deferred gains and gains on disposal of businesses	0	0	0	0
Total revenues	114.8	111.3	226.8	219.7
Benefits, losses and expenses
Policyholder benefits	65	61.9	131.7	128.1
Amortization of deferred acquisition costs and value of business acquired	17.2	16.3	33.7	28.9
Underwriting, general and administrative expenses	13.8	14.3	30	29.2
Interest expense	0	0	0	0
Total benefits, losses and expenses	96	92.5	195.4	186.2
Segment income before provision for income tax	18.8	18.8	31.4	33.5
Provision (benefit) for income taxes	4.1	6	6.9	10.8
Net income	14.7	12.8	24.5	22.7
Less: Preferred stock dividends	0		0
Net income attributable to common stockholders	14.7		24.5
Segment assets	6,897.3		6,897.3
Total Corporate and Other
Revenues
Net earned premiums	0.1	1.7	0.4	5.2
Fees and other income	0.8	8	2.1	14.2
Net investment income	15.2	13.5	27.3	24.2
Net realized gains on investments	(11.4)	13.2	(10.9)	16.6
Amortization of deferred gains and gains on disposal of businesses	15	23.4	33.5	60.4
Total revenues	19.7	59.8	52.4	120.6
Benefits, losses and expenses
Policyholder benefits	(0.9)	(11.8)	(3.7)	(31.9)
Amortization of deferred acquisition costs and value of business acquired	0	0	0	0
Underwriting, general and administrative expenses	110.9	43.9	163.6	84.9
Interest expense	26	12.4	47.5	25
Total benefits, losses and expenses	136	44.5	207.4	78
Segment income before provision for income tax	(116.3)	15.3	(155)	42.6
Provision (benefit) for income taxes	(27.9)	4.3	(35.8)	12
Net income	(88.4)	11	(119.2)	30.6
Less: Preferred stock dividends	(4.8)		(4.8)
Net income attributable to common stockholders	(93.2)		(124)
Segment assets	10,972.4		10,972.4
Total Corporate and Other | Corporate & Other
Revenues
Net earned premiums	0	0	0	0
Fees and other income	0.6	6.9	1.8	11.8
Net investment income	14.6	9.8	25.6	19.4
Net realized gains on investments	(11.4)	13.2	(10.9)	16.6
Amortization of deferred gains and gains on disposal of businesses	15	23.4	33.5	60.4
Total revenues	18.8	53.3	50	108.2
Benefits, losses and expenses
Policyholder benefits	0	0	0	0
Amortization of deferred acquisition costs and value of business acquired	0	0	0	0
Underwriting, general and administrative expenses	109.4	29.9	160.4	57.5
Interest expense	26	12.4	47.5	25
Total benefits, losses and expenses	135.4	42.3	207.9	82.5
Segment income before provision for income tax	(116.6)	11	(157.9)	25.7
Provision (benefit) for income taxes	(28)	3.5	(36.5)	6.5
Net income	(88.6)	7.5	(121.4)	19.2
Less: Preferred stock dividends	(4.8)		(4.8)
Net income attributable to common stockholders	(93.4)		(126.2)
Segment assets	10,911.2		10,911.2
Total Corporate and Other | Health
Revenues
Net earned premiums	0.1	1.7	0.4	5.2
Fees and other income	0.2	1.1	0.3	2.4
Net investment income	0.6	3.7	1.7	4.8
Net realized gains on investments	0	0	0	0
Amortization of deferred gains and gains on disposal of businesses	0	0	0	0
Total revenues	0.9	6.5	2.4	12.4
Benefits, losses and expenses
Policyholder benefits	(0.9)	(11.8)	(3.7)	(31.9)
Amortization of deferred acquisition costs and value of business acquired	0	0	0	0
Underwriting, general and administrative expenses	1.5	14	3.2	27.4
Interest expense	0	0	0	0
Total benefits, losses and expenses	0.6	2.2	(0.5)	(4.5)
Segment income before provision for income tax	0.3	4.3	2.9	16.9
Provision (benefit) for income taxes	0.1	0.8	0.7	5.5
Net income	0.2	$ 3.5	2.2	$ 11.4
Less: Preferred stock dividends	0		0
Net income attributable to common stockholders	0.2		2.2
Segment assets	$ 61.2		$ 61.2

Contract Revenues - Narrative (

Contract Revenues - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Receivables from contracts with customers	$ 134.9	$ 134.9
Unearned revenue from contracts with customers	32.3	32.3
Upfront costs in connection with client contracts	664.8	664.8	$ 288.6
Global Housing
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Disaggregated fee revenues	84.2	160.3
Global Lifestyle
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Disaggregated fee revenues	151.2	$ 324.8
Protection products
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percentage of total revenue		80.00%
Service contracts and sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percentage of total revenue		20.00%
Contract with customer, liability, revenue recognized	4.5	$ 13
Upfront costs in connection with client contracts	$ 13.6	$ 13.6

Investments (Amortized Cost, Gr

Investments (Amortized Cost, Gross Unrealized Gains and Losses, Fair Value and OTTI) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	$ 10,777	$ 8,756.5
Fixed maturity securities, fair value	11,297.5	9,662.6
Equity securities, cost or amortized cost		316.3
Equity securities, fair value		368
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	10,777	8,756.5
Fixed maturity securities, gross unrealized gains	605.8	924.8
Fixed maturity securities, gross unrealized losses	(85.3)	(18.7)
Fixed maturity securities, fair value	11,297.5	9,662.6
OTTI in AOCI	21.4	27.6
Fixed maturity securities | U.S. government and government agencies and authorities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	184.1	180.6
Fixed maturity securities, gross unrealized gains	2.6	3.2
Fixed maturity securities, gross unrealized losses	(2.1)	(1.2)
Fixed maturity securities, fair value	184.6	182.6
OTTI in AOCI	0	0
Fixed maturity securities | States, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	461.6	302.3
Fixed maturity securities, gross unrealized gains	17.9	24
Fixed maturity securities, gross unrealized losses	(1.1)	(0.1)
Fixed maturity securities, fair value	478.4	326.2
OTTI in AOCI	0	0
Fixed maturity securities | Foreign governments
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	858.4	524.8
Fixed maturity securities, gross unrealized gains	62.8	72.3
Fixed maturity securities, gross unrealized losses	(1.6)	(0.3)
Fixed maturity securities, fair value	919.6	596.8
OTTI in AOCI	0	0
Fixed maturity securities | Asset-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	494.7	188.4
Fixed maturity securities, gross unrealized gains	1.2	1.9
Fixed maturity securities, gross unrealized losses	(0.7)	(0.1)
Fixed maturity securities, fair value	495.2	190.2
OTTI in AOCI	0	1
Fixed maturity securities | Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	256.4	38.6
Fixed maturity securities, gross unrealized gains	0.3	0.2
Fixed maturity securities, gross unrealized losses	(2.8)	(0.7)
Fixed maturity securities, fair value	253.9	38.1
OTTI in AOCI	0	0
Fixed maturity securities | Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	1,241.4	1,084.2
Fixed maturity securities, gross unrealized gains	16.8	32.5
Fixed maturity securities, gross unrealized losses	(21.4)	(7.3)
Fixed maturity securities, fair value	1,236.8	1,109.4
OTTI in AOCI	5.6	9.2
Fixed maturity securities | U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	5,198.1	4,774.2
Fixed maturity securities, gross unrealized gains	365.8	602.1
Fixed maturity securities, gross unrealized losses	(43.7)	(5)
Fixed maturity securities, fair value	5,520.2	5,371.3
OTTI in AOCI	15.8	17.4
Fixed maturity securities | Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, cost or amortized cost	2,082.3	1,663.4
Fixed maturity securities, gross unrealized gains	138.4	188.6
Fixed maturity securities, gross unrealized losses	(11.9)	(4)
Fixed maturity securities, fair value	2,208.8	1,848
OTTI in AOCI	$ 0	0
Equity securities
Debt Securities, Available-for-sale [Line Items]
OTTI in AOCI		0
Equity securities, cost or amortized cost		316.3
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax		52.2
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax		(0.5)
Equity securities, fair value		368
Equity securities | Common Stock
Debt Securities, Available-for-sale [Line Items]
OTTI in AOCI		0
Equity securities, cost or amortized cost		9.3
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax		8.4
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax		0
Equity securities, fair value		17.7
Equity securities | Non-redeemable preferred stocks
Debt Securities, Available-for-sale [Line Items]
OTTI in AOCI		0
Equity securities, cost or amortized cost		307
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax		43.8
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax		(0.5)
Equity securities, fair value		$ 350.3

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018USD ($)investmentstate	Dec. 31, 2017USD ($)investmentstate
Investment [Line Items]
Number of individual states exceeding overall investment portfolio exposure | state	0	0
Maximum individual state exposure	0.50%	0.40%
Advance refunded or escrowed-to-maturity securities	$ 98.3	$ 137.7
Percentage of revenue securities	60.00%	53.00%
Investment in securities	$ 11,297.5	$ 9,662.6
Percentage of securities representing gross unrealized losses	2.00%	1.00%
Percentage of gross unrealized losses in a continuous loss position less than twelve months	82.00%	61.00%
Individual securities comprising total gross unrealized losses | investment	3,145	679
Percentage of residential mortgage-backed holdings exposure to sub-prime mortgage collateral	35.00%
Minimum
Investment [Line Items]
Outstanding balance of commercial mortgage loans (less than $1.0 million)	$ 0.1	$ 0.1
Maximum
Investment [Line Items]
Outstanding balance of commercial mortgage loans (less than $1.0 million)	12.6	12.7
Equity securities
Investment [Line Items]
Carrying value of securities	47.8	36.1
Europe | Corporate Fixed Maturity and Equity Securities
Investment [Line Items]
Investment in securities	785.2
Unrealized gain (loss) on investments	$ 31.4	58.9
Investment in securities		$ 578.4
Geographic Concentration Risk | Investments | Canada | Foreign Government Fixed Maturity Securities
Investment [Line Items]
Percentage of investments held	52.00%	79.00%
Geographic Concentration Risk | Investments | Brazil | Foreign Government Fixed Maturity Securities
Investment [Line Items]
Percentage of investments held	18.00%	12.00%
Geographic Concentration Risk | Investments | Germany | Foreign Government Fixed Maturity Securities
Investment [Line Items]
Percentage of investments held	16.00%	4.00%
Geographic Concentration Risk | Investments | Other Countries (more than 3%) | Foreign Government Fixed Maturity Securities
Investment [Line Items]
Percentage of investments held	6.00%	3.00%
Geographic Concentration Risk | Investments | United Kingdom | Corporate Fixed Maturity and Equity Securities
Investment [Line Items]
Percentage of investments held	4.00%
Investment Sector Concentration Risk | Investments | Europe | Financial Services Sector | Corporate Fixed Maturity and Equity Securities
Investment [Line Items]
Percentage of investments held	31.00%	24.00%

Investments (Amortized Cost and

Investments (Amortized Cost and Fair Value of Fixed Maturity Securities by Contractual Maturity) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Due in one year or less, cost or amortized cost	$ 320.5
Due after one year through five years, cost or amortized cost	2,276.5
Due after five years through ten years, cost or amortized cost	2,314.2
Due after ten years, cost or amortized cost	3,873.3
Total, cost or amortized cost	8,784.5
Fixed maturity securities, cost or amortized cost	10,777	$ 8,756.5
Due in one year or less, fair value	322.1
Due after one year through five years, fair value	2,294.7
Due after five years through ten years, fair value	2,338.8
Due after ten years, fair value	4,356
Total, fair value	9,311.6
Total fair value	11,297.5	$ 9,662.6
Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Cost or amortized cost	256.4
Fair value	253.9
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Cost or amortized cost	1,241.4
Fair value	1,236.8
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Cost or amortized cost	494.7
Fair value	$ 495.2

Investments (Net Realized Gains

Investments (Net Realized Gains (Losses), Including Other-Than-Temporary Impairments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments:	$ (11.4)		$ (10.9)
Net realized gains (losses) on investments:		$ 13.3		$ 17.1
Net realized losses related to other-than-temporary impairment:	0		0
Net realized losses related to other-than-temporary impairments:		(0.1)		(0.5)
Total net realized gains (losses)	(11.4)	13.2	(10.9)	16.6
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments:	(7.6)		(10.2)
Net realized gains (losses) on investments:		11.9		14.5
Net realized losses related to other-than-temporary impairment:	0		0
Net realized losses related to other-than-temporary impairments:		0		(0.4)
Equity securities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments:	(5.9)		(3.7)
Net realized gains (losses) on investments:		1.5		3.8
Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments:	1.2		2.5
Net realized gains (losses) on investments:		(0.1)		(1.2)
Net realized losses related to other-than-temporary impairment:	0		0
Net realized losses related to other-than-temporary impairments:		(0.1)		(0.1)
Consolidated investment entities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments:	0.9		$ 0.5
Net realized gains (losses) on investments:		$ 0		$ 0
Equity securities
Gain (Loss) on Securities [Line Items]
Increase (decrease) in carrying value	$ 7.8

Investments Investments (Unreal

Investments Investments (Unrealized Gains on Equity Securities) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Net losses recognized on equity securities	$ (5.9)		$ (3.7)
Less: Net realized gains related to sales of equity securities	2.3		3.7
Total unrealized gains on equity securities held	$ (8.2)	$ 9	$ (7.4)	$ 17.4

Investments (Investment Categor

Investments (Investment Category and Duration of Gross Unrealized Losses on Fixed Maturity Securities and Equity Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	$ 4,443.3
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(69.8)
Fixed maturity securities, 12 Months or More, Fair Value	331.9
Fixed maturity securities, 12 Months or More, Unrealized Losses	(15.5)
Fixed maturity securities, Total, Fair Value	4,775.2
Fixed maturity securities, Unrealized Losses	(85.3)
Available-for-sale securities, Less than 12 Months, Fair Value		$ 1,203
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(11.4)
Available-for-sale securities, 12 Months or More, Fair Value		270.8
Available-for-sale securities, 12 Months or More, Unrealized Losses		(7.3)
Available-for-sale securities, Total, Fair Value		1,473.8
Available-for-sale securities, Total, Unrealized Losses		(18.7)
Fixed maturity securities | U.S. government and government agencies and authorities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	112.7
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(1.5)
Fixed maturity securities, 12 Months or More, Fair Value	35.9
Fixed maturity securities, 12 Months or More, Unrealized Losses	(0.6)
Fixed maturity securities, Total, Fair Value	148.6
Fixed maturity securities, Unrealized Losses	(2.1)
Available-for-sale securities, Less than 12 Months, Fair Value		104.2
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(0.7)
Available-for-sale securities, 12 Months or More, Fair Value		43.3
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.5)
Available-for-sale securities, Total, Fair Value		147.5
Available-for-sale securities, Total, Unrealized Losses		(1.2)
Fixed maturity securities | States, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	150.8
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(0.9)
Fixed maturity securities, 12 Months or More, Fair Value	3.3
Fixed maturity securities, 12 Months or More, Unrealized Losses	(0.2)
Fixed maturity securities, Total, Fair Value	154.1
Fixed maturity securities, Unrealized Losses	(1.1)
Available-for-sale securities, Less than 12 Months, Fair Value		0
Available-for-sale securities, Less than 12 Months, Unrealized Losses		0
Available-for-sale securities, 12 Months or More, Fair Value		2.4
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.1)
Available-for-sale securities, Total, Fair Value		2.4
Available-for-sale securities, Total, Unrealized Losses		(0.1)
Fixed maturity securities | Foreign governments
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	296.8
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(1.4)
Fixed maturity securities, 12 Months or More, Fair Value	6.5
Fixed maturity securities, 12 Months or More, Unrealized Losses	(0.2)
Fixed maturity securities, Total, Fair Value	303.3
Fixed maturity securities, Unrealized Losses	(1.6)
Available-for-sale securities, Less than 12 Months, Fair Value		24.4
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(0.2)
Available-for-sale securities, 12 Months or More, Fair Value		0.8
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.1)
Available-for-sale securities, Total, Fair Value		25.2
Available-for-sale securities, Total, Unrealized Losses		(0.3)
Fixed maturity securities | Asset-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	225.4
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(0.7)
Fixed maturity securities, 12 Months or More, Fair Value	0
Fixed maturity securities, 12 Months or More, Unrealized Losses	0
Fixed maturity securities, Total, Fair Value	225.4
Fixed maturity securities, Unrealized Losses	(0.7)
Available-for-sale securities, Less than 12 Months, Fair Value		27.6
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(0.1)
Available-for-sale securities, 12 Months or More, Fair Value		0
Available-for-sale securities, 12 Months or More, Unrealized Losses		0
Available-for-sale securities, Total, Fair Value		27.6
Available-for-sale securities, Total, Unrealized Losses		(0.1)
Fixed maturity securities | Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	181.1
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(1.7)
Fixed maturity securities, 12 Months or More, Fair Value	12
Fixed maturity securities, 12 Months or More, Unrealized Losses	(1.1)
Fixed maturity securities, Total, Fair Value	193.1
Fixed maturity securities, Unrealized Losses	(2.8)
Available-for-sale securities, Less than 12 Months, Fair Value		0
Available-for-sale securities, Less than 12 Months, Unrealized Losses		0
Available-for-sale securities, 12 Months or More, Fair Value		12.4
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.7)
Available-for-sale securities, Total, Fair Value		12.4
Available-for-sale securities, Total, Unrealized Losses		(0.7)
Fixed maturity securities | Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	677.9
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(12.6)
Fixed maturity securities, 12 Months or More, Fair Value	161.1
Fixed maturity securities, 12 Months or More, Unrealized Losses	(8.8)
Fixed maturity securities, Total, Fair Value	839
Fixed maturity securities, Unrealized Losses	(21.4)
Available-for-sale securities, Less than 12 Months, Fair Value		217.3
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(2.4)
Available-for-sale securities, 12 Months or More, Fair Value		162.9
Available-for-sale securities, 12 Months or More, Unrealized Losses		(4.9)
Available-for-sale securities, Total, Fair Value		380.2
Available-for-sale securities, Total, Unrealized Losses		(7.3)
Fixed maturity securities | U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	2,037.9
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(40.9)
Fixed maturity securities, 12 Months or More, Fair Value	49.5
Fixed maturity securities, 12 Months or More, Unrealized Losses	(2.8)
Fixed maturity securities, Total, Fair Value	2,087.4
Fixed maturity securities, Unrealized Losses	(43.7)
Available-for-sale securities, Less than 12 Months, Fair Value		562.8
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(4.5)
Available-for-sale securities, 12 Months or More, Fair Value		30
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.5)
Available-for-sale securities, Total, Fair Value		592.8
Available-for-sale securities, Total, Unrealized Losses		(5)
Fixed maturity securities | Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, Less than 12 Months, Fair Value	760.7
Fixed maturity securities, Less than 12 Months, Unrealized Losses	(10.1)
Fixed maturity securities, 12 Months or More, Fair Value	63.6
Fixed maturity securities, 12 Months or More, Unrealized Losses	(1.8)
Fixed maturity securities, Total, Fair Value	824.3
Fixed maturity securities, Unrealized Losses	$ (11.9)
Available-for-sale securities, Less than 12 Months, Fair Value		266.7
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(3.5)
Available-for-sale securities, 12 Months or More, Fair Value		19
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.5)
Available-for-sale securities, Total, Fair Value		285.7
Available-for-sale securities, Total, Unrealized Losses		(4)
Equity securities | Non-redeemable preferred stocks
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less than 12 Months, Fair Value		13.8
Available-for-sale securities, Less than 12 Months, Unrealized Losses		(0.2)
Available-for-sale securities, 12 Months or More, Fair Value		8.7
Available-for-sale securities, 12 Months or More, Unrealized Losses		(0.3)
Available-for-sale securities, Total, Fair Value		22.5
Available-for-sale securities, Total, Unrealized Losses		$ (0.5)

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Liabilities		$ 37,028.4	$ 37,028.4	$ 27,561.5
Total assets	[1]	1,305.2	1,305.2	$ 746.5
CLO
Variable Interest Entity [Line Items]
Liabilities		174.3	174.3
Collateralized Loan Obligations | Consolidated investment entities
Variable Interest Entity [Line Items]
Special purpose entities capitalized amount		55
Total assets		116.2	116.2
Real estate fund | Consolidated investment entities
Variable Interest Entity [Line Items]
Total assets		83.6	83.6
Unfunded commitments		$ 4.1	$ 4.1
6.0% CLO November 2017 | Collateralized Loan Obligations | Consolidated investment entities
Variable Interest Entity [Line Items]
Investment percentage in most subordinated debt tranche			6.00%
9.4% CLO April 2018 | Collateralized Loan Obligations | Consolidated investment entities
Variable Interest Entity [Line Items]
Investment percentage in most subordinated debt tranche			9.40%
[1]	The following table presents information on assets and liabilities related to consolidated investment entities as of June 30, 2018 and December 31, 2017

Variable Interest Entities - Fa

Variable Interest Entities - Fair Value of Financial Assets and Liabilities (Details) - Recurring - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Total financial assets	$ 14,735	$ 12,916.2
Financial Liabilities	1,943.4	1,929.3
Consolidated investment entities
Variable Interest Entity [Line Items]
Total financial assets	1,235.7	709.5
Financial Liabilities	941.3	450.7
Consolidated investment entities | Collateralized loan obligation notes
Variable Interest Entity [Line Items]
Financial Liabilities	941.3	450.7
Consolidated investment entities | Cash and cash equivalents
Variable Interest Entity [Line Items]
Investments:	35	54.5
Consolidated investment entities | Corporate Debt Securities
Variable Interest Entity [Line Items]
Investments:	1,098.2	570.3
Consolidated investment entities | Real estate fund
Variable Interest Entity [Line Items]
Investments:	102.5	84.7
Level 1
Variable Interest Entity [Line Items]
Total financial assets	2,370.5	2,385.1
Financial Liabilities	1,748	1,706.4
Level 1 | Consolidated investment entities
Variable Interest Entity [Line Items]
Total financial assets	35	54.5
Financial Liabilities	0	0
Level 1 | Consolidated investment entities | Collateralized loan obligation notes
Variable Interest Entity [Line Items]
Financial Liabilities	0	0
Level 1 | Consolidated investment entities | Cash and cash equivalents
Variable Interest Entity [Line Items]
Investments:	35	54.5
Level 1 | Consolidated investment entities | Corporate Debt Securities
Variable Interest Entity [Line Items]
Investments:	0	0
Level 1 | Consolidated investment entities | Real estate fund
Variable Interest Entity [Line Items]
Investments:	0	0
Level 2
Variable Interest Entity [Line Items]
Total financial assets	12,168.2	10,382.4
Financial Liabilities	150	166.4
Level 2 | Consolidated investment entities
Variable Interest Entity [Line Items]
Total financial assets	1,098.2	570.3
Financial Liabilities	941.3	450.7
Level 2 | Consolidated investment entities | Collateralized loan obligation notes
Variable Interest Entity [Line Items]
Financial Liabilities	941.3	450.7
Level 2 | Consolidated investment entities | Cash and cash equivalents
Variable Interest Entity [Line Items]
Investments:	0	0
Level 2 | Consolidated investment entities | Corporate Debt Securities
Variable Interest Entity [Line Items]
Investments:	1,098.2	570.3
Level 2 | Consolidated investment entities | Real estate fund
Variable Interest Entity [Line Items]
Investments:	0	0
Level 3
Variable Interest Entity [Line Items]
Total financial assets	196.3	148.7
Financial Liabilities	45.4	56.5
Level 3 | Consolidated investment entities
Variable Interest Entity [Line Items]
Total financial assets	102.5	84.7
Financial Liabilities	0	0
Level 3 | Consolidated investment entities | Collateralized loan obligation notes
Variable Interest Entity [Line Items]
Financial Liabilities	0	0
Level 3 | Consolidated investment entities | Cash and cash equivalents
Variable Interest Entity [Line Items]
Investments:	0	0
Level 3 | Consolidated investment entities | Corporate Debt Securities
Variable Interest Entity [Line Items]
Investments:	0	0
Level 3 | Consolidated investment entities | Real estate fund
Variable Interest Entity [Line Items]
Investments:	$ 102.5	$ 84.7

Variable Interest Entities - Ca

Variable Interest Entities - Carrying value of level 3 assets (Details) - Real estate fund - Level 3 - Consolidated investment entities - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Real Estate Carrying Amount [Roll Forward]
Balance, beginning of period	$ 86.8	$ 84.7
Purchases	23	23
Sales	(6.8)	(6.8)
Total (loss) income included in earnings	(0.5)	1.6
Balance, end of period	$ 102.5	$ 102.5

Fair Value Disclosures (Fair Va

Fair Value Disclosures (Fair Value for Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 14,735	$ 12,916.2
Total financial liabilities	1,943.4	1,929.3
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	2,370.5	2,385.1
Total financial liabilities	1,748	1,706.4
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	12,168.2	10,382.4
Total financial liabilities	150	166.4
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	196.3	148.7
Total financial liabilities	45.4	56.5
Other liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	119.4	128.7
Other liabilities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	74	71.2
Other liabilities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	0	1
Other liabilities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	45.4	56.5
Liabilities related to separate accounts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	1,824	1,800.6
Liabilities related to separate accounts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	1,674	1,635.2
Liabilities related to separate accounts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	150	165.4
Liabilities related to separate accounts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial liabilities	0	0
U.S. government and government agencies and authorities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	184.6	182.6
U.S. government and government agencies and authorities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
U.S. government and government agencies and authorities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	184.6	182.6
U.S. government and government agencies and authorities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	478.4	326.2
States, municipalities and political subdivisions | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
States, municipalities and political subdivisions | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	478.4	326.2
States, municipalities and political subdivisions | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Foreign governments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	919.6	596.8
Foreign governments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0.6	1
Foreign governments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	919	595.8
Foreign governments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	495.2	190.2
Asset-backed | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Asset-backed | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	450.1	150.8
Asset-backed | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	45.1	39.4
Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	253.9	38.1
Commercial mortgage-backed | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Commercial mortgage-backed | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	194	9.5
Commercial mortgage-backed | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	59.9	28.6
Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1,236.8	1,109.4
Residential mortgage-backed | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Residential mortgage-backed | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1,236.8	1,109.4
Residential mortgage-backed | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
U.S. corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	5,520.2	5,371.3
U.S. corporate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
U.S. corporate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	5,484.8	5,350.2
U.S. corporate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	35.4	21.1
Foreign corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	2,208.8	1,848
Foreign corporate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Foreign corporate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	2,158.2	1,802.7
Foreign corporate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	50.6	45.3
Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	46
Mutual funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	46
Mutual funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0
Mutual funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0
Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	16.6	17.7
Common Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	15.9	17
Common Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0.7	0.7
Common Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Non-redeemable preferred stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	323.2	350.3
Non-redeemable preferred stocks | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Non-redeemable preferred stocks | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	321	348.1
Non-redeemable preferred stocks | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	2.2	2.2
Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	343.6	284.1
Short-term investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	91	141.6
Short-term investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	252.6	142.5
Short-term investments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Other investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	243.5	253.9
Other investments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	74	71.2
Other investments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	168	172.7
Other investments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1.5	10
Cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	637.5	544.9
Cash equivalents | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	469	519.1
Cash equivalents | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	168.5	25.8
Cash equivalents | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	3.1	2.1
Other assets | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Other assets | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1.5	0
Other assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1.6	2.1
Assets held in separate accounts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1,824	1,800.6
Assets held in separate accounts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	1,674	1,635.2
Assets held in separate accounts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	150	165.4
Assets held in separate accounts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 0	$ 0

Fair Value Disclosures (Carryin

Fair Value Disclosures (Carrying Value and Fair Value of the Financial Instruments that are Not recognized or are Not Carried at Fair Value) (Details) - Recurring - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total financial assets	$ 14,735	$ 12,916.2
Total financial liabilities	1,943.4	1,929.3
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total financial assets	2,370.5	2,385.1
Total financial liabilities	1,748	1,706.4
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total financial assets	12,168.2	10,382.4
Total financial liabilities	150	166.4
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total financial assets	196.3	148.7
Total financial liabilities	45.4	56.5
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial mortgage loans on real estate	720.1	670.2
Other investments	94.7	84.4
Other assets	45
Total financial assets	859.8	754.6
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	608.4	634.3
Funds withheld under reinsurance	347.1	179.8
Debt	2,004.8	1,068.2
Total financial liabilities	2,960.3	1,882.3
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial mortgage loans on real estate	716	679.2
Other investments	94.7	84.4
Other assets	45
Total financial assets	855.7	763.6
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	608.5	642.5
Funds withheld under reinsurance	347.1	179.8
Debt	2,084.9	1,174.4
Total financial liabilities	3,040.5	1,996.7
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial mortgage loans on real estate	0	0
Other investments	35	36.3
Other assets	0
Total financial assets	35	36.3
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	0	0
Funds withheld under reinsurance	347.1	179.8
Debt	0	0
Total financial liabilities	347.1	179.8
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial mortgage loans on real estate	0	0
Other investments	0	0
Other assets	0
Total financial assets	0	0
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	0	0
Funds withheld under reinsurance	0	0
Debt	2,084.9	1,174.4
Total financial liabilities	2,084.9	1,174.4
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commercial mortgage loans on real estate	716	679.2
Other investments	59.7	48.1
Other assets	45
Total financial assets	820.7	727.3
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	608.5	642.5
Funds withheld under reinsurance	0	0
Debt	0	0
Total financial liabilities	$ 608.5	$ 642.5

Fair Value Disclosures (Narrati

Fair Value Disclosures (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Allowance for doubtful accounts reinsurance recoverable	$ 0.3	$ 0.3
TWG Holdings Limited
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reinsurance recoverables	$ 1,580

Reserves (Roll Forward of Claim

Reserves (Roll Forward of Claims and Benefits Payable) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	May 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Claims and benefits payable, at beginning of period	$ 3,782.2	$ 3,301.2
Less: Reinsurance ceded and other	(3,193.3)	(2,718.2)
Net claims and benefits payable, at beginning of period	588.9	583
Acquired reserves as of Acquisition Date				$ 142.9	$ 0
Incurred losses and loss adjustment expenses related to:
Current year	938.1	856.3
Prior years	(30.6)	(60)
Total incurred losses and loss adjustment expenses	907.5	796.3
Paid losses and loss adjustment expenses related to:
Current year	624.6	556
Prior years	336.4	262.8
Total paid losses and loss adjustment expenses	961	818.8
Net claims and benefits payable, at end of period	678.3	560.5
Reinsurance ceded and other	3,193.3	2,718.2		3,193.3	2,718.2
Claims and benefits payable, at end of period	3,503.1	3,093.3
Claims and benefits payable	3,503.1	3,301.2		$ 3,782.2	$ 3,301.2
Plus: Reinsurance ceded and other	$ 2,824.8	$ 2,532.8
TWG Holdings Limited
Paid losses and loss adjustment expenses related to:
Reinsurance ceded and other			$ 280.6
Claims and benefits payable			$ 423.5

Reserves (Narrative) (Details)

Reserves (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2018	May 31, 2018	Dec. 31, 2017	Jun. 30, 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Goodwill	$ 2,369.2		$ 917.7
Global Housing and Global Lifestyle
Liability for Claims and Claims Adjustment Expense [Line Items]
Favorable development	29.3			$ 51.7
Global Housing
Liability for Claims and Claims Adjustment Expense [Line Items]
Goodwill	378.6		$ 386.7
Global Housing | Hurricane Matthew
Liability for Claims and Claims Adjustment Expense [Line Items]
Favorable development	2.2			5.2
Assurant Health
Liability for Claims and Claims Adjustment Expense [Line Items]
Favorable development	$ 0.7			$ 7.8
TWG Holdings Limited
Liability for Claims and Claims Adjustment Expense [Line Items]
Goodwill		$ 1,463.8

Goodwill and Other Intangible66

Goodwill and Other Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 917.7
Acquisitions	1,463.8
Impairment	(8.1)
Foreign currency translation and other	(4.2)
Goodwill, ending balance	2,369.2
Accumulated impairment losses		$ 1,260
Global Housing
Goodwill [Roll Forward]
Goodwill, beginning balance	386.7
Acquisitions	0
Impairment	(8.1)
Foreign currency translation and other	0
Goodwill, ending balance	378.6
Global Lifestyle
Goodwill [Roll Forward]
Goodwill, beginning balance	392.8
Acquisitions	1,463.8
Impairment	0
Foreign currency translation and other	(3.9)
Goodwill, ending balance	1,852.7
Global Preneed
Goodwill [Roll Forward]
Goodwill, beginning balance	138.2
Acquisitions	0
Impairment	0
Foreign currency translation and other	(0.3)
Goodwill, ending balance	$ 137.9

Goodwill and Other Intangible67

Goodwill and Other Intangible Assets - VOBA and Other Intangible Assets (Details) - USD ($) $ in Millions	May 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Value of business acquired		$ 3,962.5		$ 3,962.5		$ 24.4
Other intangible assets, net		664.8		664.8		$ 288.6
Amortization of Value of Business Acquired (VOBA)		36.3	$ 2	38	$ 4.1
Amortization of Intangible Assets		19.7	$ 18.4	39.1	$ 36.3
VOBA
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net		3,962.5		3,962.5
TWG Holdings Limited
Indefinite-lived Intangible Assets [Line Items]
Total other intangible assets	$ 461.4
Finite-Lived Intangible Assets [Line Items]
Value of business acquired	3,995.7
Finite-Lived Intangible Assets, Net	449.8
TWG Holdings Limited | License
Indefinite-lived Intangible Assets [Line Items]
Indefinite life, Licenses	$ 11.6
TWG Holdings Limited | VOBA
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net		$ 3,941.7		$ 3,941.7
Estimated Useful Life	9 years
TWG Holdings Limited | Distribution network
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 392.4
Estimated Useful Life	15 years
TWG Holdings Limited | Technology based intangibles
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 57.4
Estimated Useful Life	9 years

Goodwill and Other Intangible68

Goodwill and Other Intangible Assets - Intangible Assets Future Amortization (Details) - USD ($) $ in Millions	Jun. 30, 2018	May 31, 2018
VOBA
Finite-Lived Intangible Assets [Line Items]
Remainder of Fiscal Year	$ 214.1
2,019	526.2
2,020	638.5
2,021	696.7
2,022	760.1
2,023	766.3
Thereafter	360.6
Total	3,962.5
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Remainder of Fiscal Year	37.4
2,019	60.7
2,020	63
2,021	58.1
2,022	52.3
2,023	47.8
Thereafter	331.7
Total	651
TWG Holdings Limited
Finite-Lived Intangible Assets [Line Items]
Total		$ 449.8
TWG Holdings Limited | VOBA
Finite-Lived Intangible Assets [Line Items]
Remainder of Fiscal Year	210.6
2,019	519.6
2,020	632.2
2,021	695.9
2,022	759.4
2,023	765.7
Thereafter	358.3
Total	3,941.7
TWG Holdings Limited | Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Remainder of Fiscal Year	7.3
2,019	19.4
2,020	27.6
2,021	31.3
2,022	35
2,023	36.2
Thereafter	291
Total	447.8
AIZ excluding TWG | VOBA
Finite-Lived Intangible Assets [Line Items]
Remainder of Fiscal Year	3.5
2,019	6.6
2,020	6.3
2,021	0.8
2,022	0.7
2,023	0.6
Thereafter	2.3
Total	20.8
AIZ excluding TWG | Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Remainder of Fiscal Year	30.1
2,019	41.3
2,020	35.4
2,021	26.8
2,022	17.3
2,023	11.6
Thereafter	40.7
Total	$ 203.2

Debt (Narrative) (Details)

Debt (Narrative) (Details)		Mar. 27, 2018USD ($)series	Jun. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2018USD ($)	Mar. 15, 2018USD ($)
Debt Instrument [Line Items]
Debt outstanding			$ 2,000,000,000	$ 2,000,000,000
Net proceeds from issuance of debt	[1]			1,286,100,000	$ 69,000,000
Senior Notes
Debt Instrument [Line Items]
Number of series issued | series		3
Aggregate principal amount		$ 900,000,000
Senior Notes | Senior Notes 2021
Debt Instrument [Line Items]
Aggregate principal amount		300,000,000
Senior Notes | Senior Notes 2023
Debt Instrument [Line Items]
Aggregate principal amount		$ 300,000,000
Interest rate		4.20%
Discount rate		0.233%
Senior Notes | Senior Notes 2028
Debt Instrument [Line Items]
Aggregate principal amount		$ 300,000,000
Interest rate		4.90%
Discount rate		0.383%
Senior Notes | Senior Notes 2018
Debt Instrument [Line Items]
Aggregate principal amount							$ 350,000,000
Interest rate							2.50%
Senior Notes 2023 | Senior Notes 2023
Debt Instrument [Line Items]
Aggregate principal amount			350,000,000	350,000,000
Senior Notes 2034 | Senior Notes 2034
Debt Instrument [Line Items]
Aggregate principal amount			375,000,000	375,000,000
Subordinated notes | Subordinated Notes 2048
Debt Instrument [Line Items]
Aggregate principal amount		$ 400,000,000
Interest rate		7.00%
The Notes
Debt Instrument [Line Items]
Net proceeds from issuance of debt		$ 1,280,000,000
London Interbank Offered Rate (LIBOR) | Senior Notes | Senior Notes 2021
Debt Instrument [Line Items]
Interest rate		1.25%
London Interbank Offered Rate (LIBOR) | Subordinated notes | Subordinated Notes 2048
Debt Instrument [Line Items]
Interest rate		4.135%
Revolving Credit Facility | Senior Notes
Debt Instrument [Line Items]
Senior revolving credit facility			450,000,000	450,000,000
Revolving Credit Facility | Line of Credit | Jp Morgan Chase Bank N And Bank Of America N | The Term Loan Facility
Debt Instrument [Line Items]
Other Expenses			$ 300,000	$ 9,600,000
Bridge Loan | Line of Credit | Jp Morgan Chase Bank N And Bank Of America N | Unsecured Bridge Loan Facility
Debt Instrument [Line Items]
Credit facility borrowing capacity		$ 1,500,000,000
Series D MCPS
Debt Instrument [Line Items]
Share interest rate				6.50%
Derivative
Debt Instrument [Line Items]
Derivative qualified for hedge accounting gain (loss)				$ 26,700,000
Debt interest expense				8,600,000
Derivative | Senior Notes | Senior Notes 2021
Debt Instrument [Line Items]
Aggregate principal amount						$ 150,000,000
Interest rate						2.72%
Interest Rate Derivatives
Debt Instrument [Line Items]
Derivative qualified for hedge accounting gain (loss)				$ 25,800,000
[1]	Refer to Note 12 - Debt, for additional information.

Debt - Rating Agencies interest

Debt - Rating Agencies interest rate (Details)	6 Months Ended
	Jun. 30, 2018
Maximum
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	2.00%
BB Plus
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	0.25%
BB
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	0.50%
BB-
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	0.75%
B Plus Or Below
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	1.00%
Ba1
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	0.25%
Ba2
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	0.50%
Ba3
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	0.75%
B1 or below
Financing Receivable, Recorded Investment [Line Items]
Interest rate increase	1.00%

Accumulated Other Comprehensi71

Accumulated Other Comprehensive Income (Components of Accumulated Other Comprehensive Income, Net of Tax) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance				$ 4,270.6
Change in accumulated other comprehensive (loss) income before reclassifications		$ (194.6)	$ 95.1	(345.7)	$ 152.8
Amounts reclassified from accumulated other comprehensive (loss) income		5	(6.5)	7.7	(10.5)
Total other comprehensive (loss) income		(189.6)	88.6	(338)	142.3
Ending balance		5,312.5		5,312.5
Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles	[1]	7.5		7.5
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		51.7	148.3	234	94.6
Total other comprehensive (loss) income				(338)
Ending balance		(137.9)	236.9	(137.9)	236.9
Accumulated Other Comprehensive Income | Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles	[1]	(33.9)		(33.9)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(272.3)	(300.3)	(281.5)	(322.1)
Change in accumulated other comprehensive (loss) income before reclassifications		(83.1)	15.7	(73.9)	37.5
Amounts reclassified from accumulated other comprehensive (loss) income		0	0	0	0
Total other comprehensive (loss) income		(83.1)	15.7	(73.9)	37.5
Ending balance		(355.4)	(284.6)	(355.4)	(284.6)
Foreign currency translation adjustment | Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles		0		0
Net unrealized gains on securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		372.1	491.7	581.2	459.3
Change in accumulated other comprehensive (loss) income before reclassifications		(110.6)	80.9	(288.5)	117.1
Amounts reclassified from accumulated other comprehensive (loss) income		4.7	(7)	7.4	(10.8)
Total other comprehensive (loss) income		(105.9)	73.9	(281.1)	106.3
Ending balance		266.2	565.6	266.2	565.6
Net unrealized gains on securities | Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles		(33.9)		(33.9)
Net unrealized gains on derivative transactions
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		21.1	0	0	0
Change in accumulated other comprehensive (loss) income before reclassifications		0.5	0	21.6	0
Amounts reclassified from accumulated other comprehensive (loss) income		(0.7)	0	(0.7)	0
Total other comprehensive (loss) income		(0.2)	0	20.9	0
Ending balance		20.9	0	20.9	0
Net unrealized gains on derivative transactions | Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles		0		0
OTTI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		14.4	20.3	17.9	20.6
Change in accumulated other comprehensive (loss) income before reclassifications		(1.4)	(1.5)	(4.9)	(1.8)
Amounts reclassified from accumulated other comprehensive (loss) income		0	0	0	0
Total other comprehensive (loss) income		(1.4)	(1.5)	(4.9)	(1.8)
Ending balance		13	18.8	13	18.8
OTTI | Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles		0		0
Unamortized net (losses) on Pension Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(83.6)	(63.4)	(83.6)	(63.2)
Change in accumulated other comprehensive (loss) income before reclassifications		0	0	0	0
Amounts reclassified from accumulated other comprehensive (loss) income		1	0.5	1	0.3
Total other comprehensive (loss) income		1	0.5	1	0.3
Ending balance		(82.6)	$ (62.9)	(82.6)	$ (62.9)
Unamortized net (losses) on Pension Plans | Accounting Standards Update 2016-01 and 2014-09
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of change in accounting principles		$ 0		$ 0
[1]	Amounts relate to 1) the requirement to recognize the fair value changes of equity securities directly within income (resulting in a reclassification of unrealized gains as of December 31, 2017 between accumulated other comprehensive income ("AOCI") and retained earnings) and 2) the impact of adoption of the new revenue recognition standard for revenues from service contracts and sales of products. See Note 3 for additional information.

Accumulated Other Comprehensi72

Accumulated Other Comprehensive Income (Reclassification out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized (losses) gains on investments, excluding other-than-temporary impairment losses	$ (11.4)		$ (10.9)
Net realized (losses) gains on investments, excluding other-than-temporary impairment losses		$ 13.3		$ 17.1
Provision for income taxes	(11.3)	(58.5)	(41.8)	(129.8)
Net income	67	120.2	173	264
Interest expense	26	12.4	47.5	25
Total reclassifications for the period, net of tax	5	(6.5)	7.7	(10.5)
Net unrealized gains on securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax	4.7	(7)	7.4	(10.8)
OTTI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax	0	0	0	0
Unamortized net (losses) on Pension Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax			1.2	0.5
Provision for income taxes			0.2	0.2
Total reclassifications for the period, net of tax	1	0.5	1	0.3
Settlement gain
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax			0	(0.6)
Amortization of net loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax			1.2	1.1
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period, net of tax	5	(6.5)
Reclassification out of Accumulated Other Comprehensive Income | Net unrealized gains on securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized (losses) gains on investments, excluding other-than-temporary impairment losses	6		9.4
Net realized (losses) gains on investments, excluding other-than-temporary impairment losses		(10.8)		(16.7)
Provision for income taxes	(1.3)	3.8	(2)	5.9
Net income	4.7	(7)	7.4	(10.8)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	0.2	0	0.2	0
Interest expense	(0.9)	0	(0.9)	0
Net of tax	(0.7)	0	$ (0.7)	$ 0
Reclassification out of Accumulated Other Comprehensive Income | Unamortized net (losses) on Pension Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	(0.2)	(0.3)
Total reclassifications for the period, net of tax	1	0.5
Reclassification out of Accumulated Other Comprehensive Income | Amortization of net loss
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ 1.2	$ 0.8

Stock Based Compensation (Long-

Stock Based Compensation (Long-Term Equity Incentive Plans) (Details)	May 12, 2017shares
Long-Term Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company's common stock authorized to employees (in shares) (up to)	1,500,000

Stock Based Compensation (Restr

Stock Based Compensation (Restricted and Performance Stock Units) (Details) - Long-Term Equity Incentive Plan - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 8.7	$ 6.1	$ 13.8	$ 10.8
Income tax benefit		(1.5)	(2.1)	(2.3)	(3.8)
Compensation expense, net of tax		$ 7.2	$ 4	$ 11.5	$ 7
Granted (in shares)		32,330	31,554	421,829	205,199
Weighted average grant date fair value per unit (in dollars per share)		$ 89.56	$ 99.74	$ 90.64	$ 99.17
Fair value of awards vested		$ 2.6	$ 3.5	$ 18.8	$ 23.9
Unrecognized compensation cost		39.4		$ 39.4
Unrecognized compensation cost expected to be recognized over a weighted-average period (in years)				1 year 6 months
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		3.1	3.2	$ 7.3	0.1
Income tax benefit		(0.4)	(1.1)	(1.3)	0
Compensation expense, net of tax		$ 2.7	$ 2.1	$ 6	$ 0.1
Granted (in shares)		0	0	0	237,623
Weighted average grant date fair value per unit (in dollars per share)		$ 0	$ 0	$ 0	$ 112.32
Fair value of awards vested		$ 25.6	$ 29.4	$ 25.6	$ 29.4
Unrecognized compensation cost		$ 14.1		$ 14.1
Unrecognized compensation cost expected to be recognized over a weighted-average period (in years)				9 months 18 days
Subsequent Event | CEO and Executive Officers | Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 11.1
Subsequent Event | Chief Executive Officer | Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 4

Equity Transactions (Narrative)

Equity Transactions (Narrative) (Details) - USD ($)	1 Months Ended	6 Months Ended
	Mar. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Jul. 12, 2018
Class of Stock [Line Items]
Share repurchases (in shares)		0	2,209,636
Amount remaining under total repurchase authorization		$ 293,400,000
Acquisition of common stock			$ 216,300,000
Preferred stock, shares issued (in shares)		2,875,000
Preferred stock, par value (in dollars per share)		$ 1
Dividends payable (in dollars per share)		$ 4,800,000
Series D MCPS
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	2,875,000
Share interest rate		6.50%
Preferred stock, par value (in dollars per share)	$ 1
Public Offering price (in dollars per share)	100
Liquidation price (in dollars per share)	$ 100	$ 100
Net proceeds from sale of stock	$ 276,400,000
Series D MCPS | Over-Allotment Option
Class of Stock [Line Items]
Shares issued in period (in shares)	375,000
Minimum | Series D MCPS
Class of Stock [Line Items]
Stock conversion ratio (in shares)	0.9354
Maximum | Series D MCPS
Class of Stock [Line Items]
Stock conversion ratio (in shares)	1.1225
Initial dividend | Series D MCPS
Class of Stock [Line Items]
Dividends Payable, Amount Per Share		1.6792
Subsequent dividends | Series D MCPS
Class of Stock [Line Items]
Dividends Payable, Amount Per Share		$ 1.6250
Subsequent Event | Subsequent dividends | Series D MCPS
Class of Stock [Line Items]
Dividends Payable, Amount Per Share				$ 1.6250

Earnings Per Common Share (Net

Earnings Per Common Share (Net Income, Weighted Average Common Shares Used in Calculating Basic Earnings Per Common Share and Diluted EPS) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator
Net income	$ 67	$ 120.2	$ 173	$ 264
Less: Preferred stock dividends	(4.8)	0	(4.8)	0
Net Income (Loss) Available to Common Stockholders, Basic	62.2	120.2	168.2	264
Less: Common stock dividends paid	(30.9)	(30.3)	(60.6)	(60)
Undistributed earnings	$ 31.3	$ 89.9	$ 107.6	$ 204
Denominator
Weighted average shares outstanding used in basic earnings per share (in shares)	57,060,313	55,230,367	55,125,584	55,713,172
Incremental common shares from:
Weighted average shares used in diluted earnings per share calculations (in shares)	57,264,408	55,509,898	57,273,428	56,075,152
Earnings per common share - Basic
Distributed earnings (in dollars per share)	$ 0.54	$ 0.55	$ 1.10	$ 1.08
Undistributed earnings (in dollars per share)	0.55	1.63	1.95	3.66
Net income (in dollars per share)	1.09	2.18	3.05	4.74
Earnings per common share - Diluted
Distributed earnings (in dollars per share)	0.54	0.54	1.06	1.07
Undistributed earning (in dollars per share)	0.55	1.62	1.96	3.64
Net income (in dollars per share)	$ 1.09	$ 2.16	$ 3.02	$ 4.71
PSUs
Incremental common shares from:
Incremental common shares (in shares)	163,596	239,400	217,455	321,849
ESPP
Incremental common shares from:
Incremental common shares (in shares)	40,499	40,131	40,499	40,131
Series D MCPS
Incremental common shares from:
Mandatory convertible preferred stock (in shares)	0	0	1,889,890	0

Earnings Per Common Share (Narr

Earnings Per Common Share (Narrative) (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding anti-dilutive shares excluded from computation of diluted EPS (in shares)	4,171	97,574	4,171	74,410
Series D MCPS
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding anti-dilutive shares excluded from computation of diluted EPS (in shares)	3,056,700

Retirement and Other Employee78

Retirement and Other Employee Benefits (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Pension Plan | Qualified Pension Benefits | Qualified Pension Plan - Plan 1
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 5.8	$ 2.9	$ 11.6	$ 5.8
Expected return on plan assets	(9.1)	(6.1)	(18.2)	(12.2)
Amortization of net loss	0.2	0	0.4	0
Curtailment/settlement gain			0	0
Net periodic benefit cost	(3.1)	(3.2)	(6.2)	(6.4)
Pension Plan | Qualified Pension Benefits | Qualified Pension Plan - Plan 2
Defined Benefit Plan Disclosure [Line Items]
Interest cost		3.1		6.2
Expected return on plan assets		(6.8)		(13.6)
Amortization of net loss		0.3		0.6
Curtailment/settlement gain				0
Net periodic benefit cost		(3.4)		(6.8)
Pension Plan | Unfunded Nonqualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0.7	0.7	1.4	1.5
Expected return on plan assets	0	0	0	0
Amortization of net loss	0.3	0.3	0.8	0.6
Curtailment/settlement gain			0	(0.7)
Net periodic benefit cost	1	1	2.2	1.4
Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0.9	0.8	1.7	1.7
Expected return on plan assets	(0.6)	(0.7)	(1.1)	(1.5)
Amortization of net loss	0	0	0	0
Curtailment/settlement gain			0	0
Net periodic benefit cost	$ 0.3	$ 0.1	$ 0.6	$ 0.2

Retirement and Other Employee79

Retirement and Other Employee Benefits (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Expected long-term return on plan assets	4.75%	6.75%
Qualified pension benefits plan under-funded amount	$ 83,700,000		$ 81,300,000
Funded status percentage	112.00%		111.00%
Cash contribution to qualified pension benefits plan	$ 0
Cash expected contribution to plan over remainder of fiscal year	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Letters of credit outstanding	$ 16.9		$ 18.1
Accrual of estimated share of guaranty association assessments	6.3
Expense related to Penn Treaty	$ 1.4	$ 0.8

Income Taxes Income Taxes (Deta

Income Taxes Income Taxes (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018
Income Tax Contingency [Line Items]
TCJA, Tax expense (benefit)			$ 177
Global Lifestyle
Income Tax Contingency [Line Items]
Provision (benefit) for income taxes		$ 3.9		$ 3.9
Total Corporate and Other
Income Tax Contingency [Line Items]
Provision (benefit) for income taxes	$ 5.7			$ 5.7
TWG Holdings Limited
Income Tax Contingency [Line Items]
TCJA, Tax expense (benefit)			$ (6)

Dispositions (Details)

Dispositions (Details) - Mortgage Solutions Business - Disposal group, not discontinued operations - USD ($) $ in Millions	Aug. 01, 2018	Jun. 30, 2018
Underwriting, general and administrative expense
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss		$ 43.5
Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration	$ 35