Sun Communities (SUI) 10-Q 25 Oct 18 2018 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 18, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	SUI
Entity Registrant Name	SUN COMMUNITIES INC
Entity Central Index Key	912,593
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		86,359,824

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Land	$ 1,187,502	$ 1,107,838
Land improvements and buildings	5,523,554	5,102,014
Rental homes and improvements	559,290	528,074
Furniture, fixtures and equipment	174,315	144,953
Investment property	7,444,661	6,882,879
Accumulated depreciation	(1,390,684)	(1,237,525)
Investment property, net (including $300,693 and $50,193 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)	6,053,977	5,645,354
Cash and cash equivalents	113,556	10,127
Inventory of manufactured homes	41,030	30,430
Notes and other receivables, net	167,698	163,496
Collateralized receivables, net	112,228	128,246
Other assets, net (including $20,655 and $1,659 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)	165,237	134,304
TOTAL ASSETS	6,653,726	6,111,957
LIABILITIES
Mortgage loans payable (including $44,426 and $41,970 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)	2,819,225	2,867,356
Lines of credit		41,257
Distributions payable	63,250	55,225
Customer Advances and Deposits	135,647	132,205
Other liabilities (including $7,434 and $1,468 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)	163,459	138,536
TOTAL LIABILITIES	3,367,285	3,405,204
Commitments and contingencies	0	0
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	21,976	0
STOCKHOLDERS' EQUITY
Common stock, $0.01 par value. Authorized: 180,000 shares; Issued and outstanding: 86,355 shares at September 30, 2018 and 79,679 shares at December 31, 2017	864	797
Additional paid-in capital	4,396,092	3,758,533
Accumulated other comprehensive (loss) / income	(390)	1,102
Distributions in excess of accumulated earnings	(1,237,428)	(1,162,001)
Total Sun Communities, Inc. stockholders' equity	3,159,138	2,598,431
Noncontrolling interests:
Common and preferred OP units	56,018	60,971
Consolidated variable interest entities	7,544	4,285
Total noncontrolling interests	63,562	65,256
TOTAL STOCKHOLDERS' EQUITY	3,222,700	2,663,687
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	6,653,726	6,111,957
Series A-4 Preferred Stock
LIABILITIES
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount	31,739	32,414
Series A-4 preferred OP units
LIABILITIES
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount	10,026	10,652
Preferred Equity, Mandatorily Redeemable [Member]
LIABILITIES
Preferred OP units - mandatorily redeemable	35,277	0
Aspen Series B3 Preferred Operating Partnership Units [Member]
LIABILITIES
Mortgage loans payable (including $44,426 and $41,970 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)	37,338
Preferred OP units - mandatorily redeemable	37,338	41,443
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
LIABILITIES
Mortgage loans payable (including $44,426 and $41,970 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		129,182
Lines of credit	0
Reported Value Measurement [Member] | Secured Debt [Member]
LIABILITIES
Mortgage loans payable (including $44,426 and $41,970 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)	113,089	129,182
Collateralized Receivables [Member]
LIABILITIES
Financing Receivable, Gross	113,089
Collateralized Receivables [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
ASSETS
Collateralized receivables, net	112,228
Collateralized Receivables [Member] | Reported Value Measurement [Member]
ASSETS
Notes and other receivables, net	112,200	128,246
Collateralized Receivables [Member] | Reported Value Measurement [Member] | Secured Debt [Member] | Fair Value, Measurements, Recurring [Member]
LIABILITIES
Financing Receivable, Gross	$ 113,089	$ 129,182

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Investment property, net	$ 6,053,977	$ 5,645,354
Other assets	165,237	134,304
Secured debt	2,819,225	2,867,356
Other liabilities	$ 163,459	$ 138,536
Common Stock, Par Value	$ 0.01	$ 0.01
Common Stock, Shares Authorized	180,000	180,000
Common Stock, Shares Issued	86,355	79,679
Common Stock, Shares Outstanding	86,355	79,679
Series A-4 Preferred Stock
Series A-4 Preferred Stock, Par Value	$ 0.01	$ 0.01
Series A-4 Preferred Stock, Shares Issued	1,063	1,085
Series A-4 Preferred Stock, Shares Outstanding	1,063	1,085
Variable Interest Entity, Primary Beneficiary [Member]
Investment property, net	$ 300,693	$ 50,193
Other assets	20,655	1,659
Secured debt	44,426	41,970
Preferred OP units - mandatorily redeemable	35,277	0
Other liabilities	$ 7,434	$ 1,468

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
REVENUES
Income from real property	$ 229,607	$ 198,263	$ 625,488	$ 560,778
Revenue from home sales	46,131	33,197	122,248	91,319
Rental home revenue	13,589	12,757	39,957	37,774
Ancillary revenues	27,608	17,017	46,207	32,086
Interest	5,256	5,920	15,849	15,609
Brokerage commissions and other revenues, net	1,347	1,091	3,131	2,978
Total revenues	323,538	268,245	852,880	740,544
EXPENSES
Property operating and maintenance	71,364	59,249	181,579	159,861
Real estate taxes	14,533	13,053	42,445	39,322
Cost of home sales	33,692	25,094	91,195	67,999
Rental home operating and maintenance	6,139	6,775	16,577	16,821
Ancillary expenses	15,361	10,086	28,985	21,995
Home selling expenses	4,043	3,290	11,319	9,391
General and administrative	20,127	18,174	61,432	55,912
Transaction costs	24	2,167	138	6,990
Depreciation and amortization	71,982	64,232	206,192	189,719
Loss on extinguishment of debt	939	0	2,657	759
Interest	33,521	32,085	96,919	95,765
Interest on mandatorily redeemable preferred OP units / equity	1,142	790	2,551	2,361
Total expenses	273,040	242,751	740,002	675,019
Income before other items	50,498	25,494	112,878	65,525
Catastrophic weather related charges	173	7,756	1,987	8,124
Other income / (expense), net	1,231	3,345	(3,214)	5,340
Current tax (expense) / benefit	(213)
Provision for state income taxes	200	38	(612)	(133)
Deferred tax benefit	199	81	434	745
Net income	51,715	28,958	109,486	71,477
Less: Preferred return to preferred OP units	(1,152)	(1,112)	(3,335)	(3,482)
Less: Amounts attributable to noncontrolling interests	(4,071)	(1,776)	(8,392)	(4,179)
Net income attributable to Sun Communities, Inc.	46,492	26,070	97,759	63,816
Less: Preferred stock distribution	(432)	(1,955)	(1,305)	(6,233)
Net income attributable to Sun Communities, Inc. common stockholders	$ 46,060	$ 24,115	$ 96,454	$ 57,583
Weighted average common shares outstanding:
Basic	81,599	78,369	80,022	75,234
Diluted	82,081	78,808	80,024	75,846
Earnings per share:
Basic	$ 0.56	$ 0.31	$ 1.19	$ 0.76
Diluted	$ 0.56	$ 0.31	$ 1.19	$ 0.76

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 51,715	$ 28,958	$ 109,486	$ 71,477
Foreign currency translation adjustment	1,890	2,648	(1,565)	4,977
Total comprehensive income	53,605	31,606	107,921	76,454
Less: Comprehensive income attributable to noncontrolling interests	4,167	1,912	8,319	4,444
Comprehensive income attributable to Sun Communities, Inc.	$ 49,438	$ 29,694	$ 99,602	$ 72,010

Consolidated Statement Of Stock

Consolidated Statement Of Stockholders' Equity - 9 months ended Sep. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Distributions in Excess of Accumulated Earnings	Accumulated Other Comprehensive Income / (Loss)	Noncontrolling Interests	Common OP Units	Series A-4 Preferred Stock
Temporary equity, beginning balance at Dec. 31, 2017	$ 43,066
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of stock							$ (342)	$ (675)
Equity Interests - NG Sun LLC	21,976
Net income	225
Distributions	(509)
Temporary equity, ending balance at Sep. 30, 2018	63,741
Balance at Dec. 31, 2017	2,663,687	$ 797	$ 3,758,533	$ (1,162,001)	$ 1,102	$ 65,256
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock and common OP units, net	624,152	$ 66	624,086
Conversion of units		1
Conversion of OP units	(342)		(1,488)			(1,147)
Conversion of Series A-4 preferred stock	675		675
Share-based compensation - amortization and forfeitures	11,557		11,310	247
Foreign currency translation	(1,565)				(1,492)	(73)
Net income	109,261			101,093		8,168
Distributions	(185,409)			(176,767)		(8,642)
Balance at Sep. 30, 2018	$ 3,222,700	$ 864	$ 4,396,092	$ (1,237,428)	$ (390)	$ 63,562

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended	9 Months Ended		12 Months Ended
	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
OPERATING ACTIVITIES:
NET CASH PROVIDED BY OPERATING ACTIVITIES		$ 301,204	$ 226,142
INVESTING ACTIVITIES:
Investment in properties		(257,017)	(203,233)
Acquisitions of properties, net of cash acquired		(305,724)	(70,328)
Proceeds from dispositions of assets and depreciated homes, net		34,825	6,592
Purchases of notes receivable		(216)	(2,480)
Repayments of notes and other receivables		2,880	1,764
Investment in affiliates		(19,851)	0
NET CASH USED FOR INVESTING ACTIVITIES		(545,103)	(267,685)
FINANCING ACTIVITIES:
Issuance of common stock, OP units, and preferred OP units, net		624,152	457,638
Borrowings on lines of credit		1,187,098	575,351
Payments on lines of credit		(1,228,907)	(675,695)
Proceeds from issuance of other debt		228,336	85,081
Payments on other debt		(273,380)	(72,024)
Prepayment penalty on debt		(2,024)	(759)
Redemption of Series A-4 preferred stock and OP units			(24,698)
Distributions to stockholders, OP unit holders, and preferred OP unit holders		(177,926)	(165,937)
Payments for deferred financing costs		(1,645)	(5,589)
Proceeds from (Payments for) Other Financing Activities		(2,021)	0
NET CASH PROVIDED BY FINANCING ACTIVITIES		349,578	173,368
Effect of exchange rate changes on cash, cash equivalents and restricted cash		(94)	253
Net change in cash, cash equivalents and restricted cash		105,585	132,078
Cash, cash equivalents and restricted cash, beginning of period	$ 23,509	23,509	25,313	$ 25,313
Cash, cash equivalents and restricted cash, end of period		129,094	157,391	23,509
SUPPLEMENTAL INFORMATION:
Cash paid for interest (net of capitalized interest of $3,216 and $1,981 respectively)		94,801	92,362
Cash paid for interest on mandatorily redeemable debt		2,551	2,361
Cash paid (refunds) for income taxes		741	(53)
Noncash investing and financing activities:
Reduction in secured borrowing balance		16,093	17,674
Change in distributions declared and outstanding		7,991	4,527
Conversion of common and preferred OP units		1,489	3,240
Conversion of Series A-4 Preferred Stock		675	4,720
Acquisitions - Common stock and OP units issued		0	28,410
Acquisitions - debt assumed		3,120		$ 4,592
Acquisitions - receivable due from seller		0	5,000
Series B-3 Preferred OP Units [Member]
FINANCING ACTIVITIES:
Redemption of Series A-4 preferred stock and OP units		(4,105)	0
Series B Preferred Stock [Member]
Noncash investing and financing activities:
Noncash Or Part Noncash Acquisition, Noncash Financial Or Equity Instrument Consideration, Value Of Shares Issued		21,976	0
Series A Preferred Stock [Member]
Noncash investing and financing activities:
Noncash Or Part Noncash Acquisition, Noncash Financial Or Equity Instrument Consideration, Value Of Shares Issued	$ 35,277		$ 0
Series A-4 Preferred Stock and OP Units [Member]
FINANCING ACTIVITIES:
Redemption of Series A-4 preferred stock and OP units		$ 0

Consolidated Statements Of Ca_2

Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Capitalized interest	$ 3,216	$ 1,981

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Sun Communities, Inc., a Maryland corporation, and all wholly-owned or majority-owned and controlled subsidiaries, including Sun Communities Operating Limited Partnership (the “Operating Partnership”) and Sun Home Services, Inc. (“SHS”) are referred to herein as the “Company,” “us,” “we,” and “our.” We follow accounting standards set by the Financial Accounting Standards Board (“FASB”). FASB sets generally accepted accounting principles (“GAAP”), which we follow to ensure that we consistently report our financial condition, results of operations, and cash flows. References to GAAP issued by the FASB in these footnotes are to the FASB Accounting Standards Codification (“ASC”). These unaudited Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial information and in accordance with GAAP. Pursuant to the SEC rules and regulations we present interim disclosures and certain information and footnote disclosures as required. Accordingly, the unaudited Consolidated Financial Statements do not include all of the information and footnotes required by GAAP for complete financial statements. The accompanying unaudited Consolidated Financial Statements reflect, in the opinion of management, all adjustments, including adjustments of a normal and recurring nature, necessary for a fair presentation of the interim financial statements. All intercompany transactions have been eliminated in consolidation. Certain reclassifications have been made to prior period financial statements in order to conform to current period presentation. The results of operations for interim periods are not necessarily indicative of results that may be expected for any other interim period or for the full year. These unaudited Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017 as filed with the SEC on February 22, 2018 (the “ 2017 Annual Report”). These statements have been prepared on a basis that is substantially consistent with the accounting principles applied in our 2017 Annual Report.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Disaggregation of Revenue The following tables disaggregates our revenue by major source (in thousands): Three Months Ended Three Months Ended Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated REVENUE Income from real property $ 229,607 $ — $ 229,607 $ 198,263 $ — $ 198,263 Revenue from home sales — 46,131 46,131 — 33,197 33,197 Rental home revenue — 13,589 13,589 — 12,757 12,757 Ancillary revenues 27,608 — 27,608 17,017 — 17,017 Interest 5,256 — 5,256 5,920 — 5,920 Brokerage commissions and other revenues, net 1,347 — 1,347 1,091 — 1,091 Total revenue $ 263,818 $ 59,720 $ 323,538 $ 222,291 $ 45,954 $ 268,245 Nine Months Ended Nine Months Ended Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated REVENUE Income from real property $ 625,488 $ — $ 625,488 $ 560,778 $ — $ 560,778 Revenue from home sales — 122,248 122,248 — 91,319 91,319 Rental home revenue — 39,957 39,957 — 37,774 37,774 Ancillary revenues 46,207 — 46,207 32,086 — 32,086 Interest 15,849 — 15,849 15,609 — 15,609 Brokerage commissions and other revenues, net 3,131 — 3,131 2,978 — 2,978 Total revenue $ 690,675 $ 162,205 $ 852,880 $ 611,451 $ 129,093 $ 740,544 Revenue Recognition Policies and Performance Obligations On January 1, 2018, we adopted FASB Accounting Standards Update (“ASU”) 2014-09 “Revenue from Contracts with Customers” and the other related ASUs and amendments to the codification (collectively “ASC 606”). The core principle of ASC 606 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. A five-step transactional analysis is required to determine how and when to recognize revenue. ASC 606 applies to all contracts with customers, except those that are within the scope of other topics in the FASB accounting standards codification. As a real estate owner and operator, the majority of our revenue is derived from site and home leases that are accounted for pursuant to ASC 840 “Leases.” For transactions in the scope of ASC 606, we recognize revenue when control of goods or services transfers to the customer, in the amount that we expect to receive for the transfer of goods or provision of services. The adoption of ASC 606 did not result in any change to our accounting policies for revenue recognition. Accordingly, retrospective application to prior periods or a cumulative catch-up adjustment was unnecessary. Income from real property - Residents in our communities lease the site on which their home is located, and either own or lease their home. Lease revenues for sites and homes fall under the scope of ASC 840, and are accounted for as operating leases with straight-line recognition. Resident leases are generally for one-year or month-to-month terms, and are renewable by mutual agreement from us and the resident, or in some cases, as provided by jurisdictional statute. Non-lease components of our site lease contracts, which are primarily provision of utility services, are accounted for with the site lease as a single lease under ASC 840. Additionally, we include collections of real estate taxes from residents within Income from real property. Revenue from home sales - Our taxable REIT subsidiary, SHS, sells manufactured homes (“MH”) to current and prospective residents in our communities. Prior to adoption of ASC 606, we recognized revenue for home sales pursuant to ASC 605 “Revenue Recognition,” as manufactured homes are tangible personal property that can be located on any land parcel. Manufactured homes are not permanent fixtures or improvements to the underlying real estate, and were therefore not considered to be subject to the guidance in ASC 360-20 “Real Estate Sales” by the Company. In accordance with the core principle of ASC 606, we recognize revenue from home sales at the time of closing when control of the home transfers to the customer. After closing of the sale transaction, we have no remaining performance obligation. Rental home revenue - is comprised of rental agreements whereby we lease homes to residents in our communities. We account for these revenues under ASC 840. Ancillary revenues - are primarily composed of proceeds from restaurant, golf, merchandise and other activities at our recreational vehicle (“RV”) communities. Revenues are recognized at point of sale when control of the good or service transfers to the customer and our performance obligation is satisfied. Sales and other taxes that we collect concurrent with revenue-producing activities are excluded from transaction price. Interest income - is earned primarily on our notes and collateralized receivables, which includes installment loans for manufactured homes purchased by the Company from loan originators and transferred loans that previously did not meet the requirements for sale accounting. Interest income on these receivables is accrued based on the unpaid principal balances of the underlying loans on a level yield basis over the life of the loans. Interest income is not in the scope of ASC 606. Refer to Notes 4 , “Collateralized Receivables and Transfers of Financial Assets” and 5 , “Notes and Other Receivables” for additional information. Broker commissions and other revenues, net - is primarily comprised of brokerage commissions for sales of manufactured homes, where we act as agent and arrange for a third-party to transfer a manufactured home to a customer within one of our communities. Brokerage commission revenues are recognized on a net basis at closing, when the transaction is completed and our performance obligations have been fulfilled. Loan loss reserve expenses for our collateralized receivables and notes receivables are also included herein. Refer to Notes 4 , “Collateralized Receivables and Transfers of Financial Assets” and 5 , “Notes and Other Receivables” for additional information regarding our loan loss reserves. Contract Balances As of September 30, 2018 and December 31, 2017, we had $19.8 million and $13.8 million , respectively, of receivables from contracts with customers. Receivables from contracts with customers are presented as a component of Notes and other receivables on our Consolidated Balance Sheets. These receivables represent balances owed to us for previously completed performance obligations for sales of manufactured homes. Due to the nature of our revenue from contacts with customers, we do not have material contract assets or liabilities that fall under the scope of ASC 606.

Real Estate Acquisitions

Real Estate Acquisitions	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Real Estate Acquisitions	Real Estate Acquisitions 2018 Acquisitions In 2018 we acquired the following communities: Community Name Type Sites Development Sites State Month Acquired Archview RV 114 50 UT August Petoskey KOA RV 210 — MI August The Sands RV and Golf Resort RV (Age Restricted) 507 — CA July Sun NG RV Resorts LLC (1) RV 2,700 940 Various June Silver Creek RV 264 176 MI June Highway West (Four Resorts) RV 536 — UT & OR June Compass RV RV 175 — FL May Total 4,506 1,166 (1) Refer to Note 8, “Consolidated Variable Interest Entities,” Note 9, “Debt and Lines of Credit,” and Note 10, “Equity and Mezzanine Securities” for additional information. The following table summarizes the amounts of assets acquired net of liabilities assumed at the acquisition date and the consideration paid for the acquisitions completed in 2018 (in thousands): At Acquisition Date Archview Petoskey KOA Sands Sun NG Resorts Silver Creek Highway West Compass Total Investment in property $ 14,550 $ 9,000 $ 13,790 $ 240,649 $ 7,250 $ 36,500 $ 13,930 $ 335,669 In-place leases and other intangible assets — — 460 16,339 — — 70 16,869 Debt assumed — — — (3,120 ) — — — (3,120 ) Other liabilities, net — — — (11,990 ) — — — (11,990 ) Total identifiable assets acquired net of liabilities assumed $ 14,550 $ 9,000 $ 14,250 $ 241,878 $ 7,250 $ 36,500 $ 14,000 $ 337,428 Consideration Cash $ 14,550 $ 9,000 $ 14,250 $ 184,625 $ 7,250 $ 36,500 $ 14,000 $ 280,175 Preferred Equity - Sun NG Resorts — — — 35,277 — — — 35,277 Equity Interests - NG Sun LLC — — — 21,976 — — — 21,976 Total consideration $ 14,550 $ 9,000 $ 14,250 $ 241,878 $ 7,250 $ 36,500 $ 14,000 $ 337,428 In 2018, we acquired the following land for expansion / development: Name Location Type Expansion / Development Sites Cost (millions) Month Acquired Pecan Park Jacksonville, FL RV 158 $ 1.3 September Smith Creek Crossing Granby, CO MH 310 $ 0.9 September River Run Ranch Granby, CO MH / RV 1,144 $ 5.3 May Total 1,612 $ 7.5 Refer to Note 18 , “Subsequent Events,” for information regarding real estate acquisition activity after September 30, 2018. The total amount of revenues and net income included in the Consolidated Statements of Operations for the three and nine months ended September 30, 2018 related to the acquisitions completed in 2018 are set forth in the following table (in thousands): Three Months Ended Nine Months Ended (unaudited) (unaudited) Total revenues $ 26,317 $ 33,433 Net income $ 7,529 $ 11,356 The following unaudited pro forma financial information presents the results of our operations for the three and nine months ended September 30, 2018 and 2017, as if the properties acquired in 2018 had been acquired on January 1, 2017. The unaudited pro forma results reflect certain adjustments for items that are not expected to have a continuing impact, such as adjustments for transaction costs incurred, management fees, and purchase accounting. The information presented below has been prepared for comparative purposes only and does not purport to be indicative of either future results of operations or the results of operations that would have actually occurred had the acquisition been consummated on January 1, 2017 (in thousands, except per-share data): Three Months Ended September 30, Nine Months Ended September 30, (unaudited) (unaudited) 2018 2017 2018 2017 Total revenues $ 325,504 $ 296,322 $ 861,193 $ 780,529 Net income attributable to Sun Communities, Inc. common stockholders $ 57,413 $ 42,987 $ 93,714 $ 68,378 Net income per share attributable to Sun Communities, Inc. common stockholders - basic $ 0.70 $ 0.55 $ 1.17 $ 0.91 Net income per share attributable to Sun Communities, Inc. common stockholders - diluted $ 0.70 $ 0.55 $ 1.17 $ 0.90 2017 Acquisitions In 2017, we acquired the following communities: Community Name Type Sites Development Sites State Month Acquired Colony in the Wood MH (Age Restricted) 383 — FL December Emerald Coast MH and RV 201 14 FL November Lazy J Ranch MH (Age Restricted) 220 — CA September Ocean West MH (Age Restricted) 130 4 CA September Caliente Sands MH (Age Restricted) 118 — CA September Pismo Dunes RV (Age Restricted) 331 — CA July Arbor Woods MH 458 — MI June Sunset Lakes RV 498 — IL May 49er Village RV 328 — CA March Total 2,667 18 The following table summarizes the amounts of assets acquired net of liabilities assumed at the acquisition date and the consideration paid for the acquisitions completed in 2017 (in thousands): At Acquisition Date Colony in the Wood Emerald Coast Lazy J Ranch Ocean West Caliente Sands Pismo Dunes Arbor Woods Sunset Lakes 49er Village Total Investment in property $ 31,818 $ 19,400 $ 13,938 $ 9,453 $ 8,640 $ 21,260 $ 15,725 $ 7,835 $ 12,890 $ 140,959 Notes receivable — — — — — — 23 — — 23 Inventory of manufactured homes — — 2 — 21 — 465 — — 488 In-place leases and other intangible assets 660 100 360 220 210 660 730 210 110 3,260 Total identifiable assets acquired net of liabilities assumed $ 32,478 $ 19,500 $ 14,300 $ 9,673 $ 8,871 $ 21,920 $ 16,943 $ 8,045 $ 13,000 $ 144,730 Consideration Cash $ 32,478 $ 19,500 $ 14,300 $ 5,081 $ 8,871 $ — $ 14,943 $ 8,045 $ 13,000 $ 116,218 Equity — — — — — 26,410 2,000 — — 28,410 Liabilities assumed — — — 4,592 — 510 — — — 5,102 Cash proceeds from seller — — — — — (5,000 ) — — — (5,000 ) Total consideration $ 32,478 $ 19,500 $ 14,300 $ 9,673 $ 8,871 $ 21,920 $ 16,943 $ 8,045 $ 13,000 $ 144,730 In 2017, we acquired the following land for expansion: Development Name Location Type Development Sites Cost (millions) Month Acquired Carolina Pines Myrtle Beach, SC RV 841 $ 5.9 April Total 841

Collateralized Receivables and

Collateralized Receivables and Transfers of Financial Assets	9 Months Ended
	Sep. 30, 2018
Transfers and Servicing [Abstract]
Transfers Of Financial Assets	Transfers of Financial Assets We previously completed various transactions with an unrelated entity involving our notes receivable under which we received cash proceeds in exchange for relinquishing our right, title, and interest in certain notes receivable. We have no further obligations or rights with respect to the control, management, administration, servicing, or collection of the installment notes receivable. However, we are subject to certain recourse provisions requiring us to purchase the underlying homes collateralizing such notes, in the event of a note default and subsequent repossession of the home by the unrelated entity. The recourse provisions are considered to be a form of continuing involvement, and therefore these transferred loans did not meet the requirements for sale accounting. We continue to recognize these transferred loans on our balance sheet and refer to them as collateralized receivables. The proceeds from the transfer have been recognized as a secured borrowing. In the event of a note default and subsequent repossession of a manufactured home by the unrelated entity, the terms of the agreement require us to repurchase the manufactured home. Default is defined as the failure to repay the installment note receivable according to contractual terms. The repurchase price is calculated as a percentage of the outstanding principal balance of the collateralized receivable, plus any outstanding late fees, accrued interest, legal fees, and escrow advances associated with the installment note receivable. The percentage used to determine the repurchase price of the outstanding principal balance on the installment note receivable is based on the number of payments made on the note. In general, the repurchase price is determined as follows: Number of Payments Repurchase Percentage Fewer than or equal to 15 100 % Greater than 15 but fewer than 64 90 % Equal to or greater than 64 but fewer than 120 65 % 120 or more 50 % The transferred assets have been classified as Collateralized receivables, net and the cash proceeds received from these transactions have been classified as Secured borrowings on collateralized receivables within the Consolidated Balance Sheets. The balance of the collateralized receivables was $112.2 million (net of allowance of $0.9 million ) and $128.2 million (net of allowance of $0.9 million ) as of September 30, 2018 and December 31, 2017 , respectively. The receivables have a weighted average interest rate and maturity of 10.0 percent and 14.3 years as of September 30, 2018 , and 10.0 percent and 15.3 years as of December 31, 2017 . The outstanding balance on the secured borrowing was $113.1 million and $129.2 million as of September 30, 2018 and December 31, 2017 , respectively. The collateralized receivables earn interest income, and the secured borrowings accrue interest expense at the same interest rates. The amount of interest income and expense recognized was $2.8 million and $3.3 million for the three months ended September 30, 2018 and 2017 , respectively, and $8.5 million and $9.9 million for the nine months ended September 30, 2018 and 2017, respectively. The balances of the collateralized receivables and secured borrowings are reduced as the related collateralized receivables are collected from the customers, or as the underlying collateral is repurchased. The change in the aggregate gross principal balance of the collateralized receivables is as follows (in thousands): Nine Months Ended Beginning balance $ 129,182 Principal payments and payoffs from our customers (9,386 ) Principal reduction from repurchased homes (6,707 ) Total activity (16,093 ) Ending balance $ 113,089 The following table sets forth the allowance for the collateralized receivables as of September 30, 2018 (in thousands): Nine Months Ended Beginning balance $ (936 ) Lower of cost or market write-downs 587 Increase to reserve balance (512 ) Total activity 75 Ending balance $ (861 )

Notes And Other Receivables

Notes And Other Receivables	9 Months Ended
	Sep. 30, 2018
Long-term Notes and Loans, by Type, Current and Noncurrent [Abstract]
Notes And Other Receivables	Notes and Other Receivables The following table sets forth certain information regarding notes and other receivables (in thousands): September 30, 2018 December 31, 2017 Installment notes receivable on manufactured homes, net $ 117,583 $ 115,797 Other receivables, net 50,115 47,699 Total notes and other receivables, net $ 167,698 $ 163,496 Installment Notes Receivable on Manufactured Homes Our investment in installment notes of $117.6 million (net of allowance of $0.6 million ) and $115.8 million (net of allowance of $0.4 million ) as of September 30, 2018 and December 31, 2017 , respectively, are collateralized by manufactured homes. The notes represent financing to purchasers of manufactured homes primarily located in our communities and require monthly principal and interest payments. The notes have a net weighted average interest rate (net of servicing costs) and maturity of 8.0 percent and 16.8 years as of September 30, 2018 , and 8.2 percent and 17.2 years as of December 31, 2017 , respectively. The change in the aggregate gross principal balance of the installment notes receivable is as follows (in thousands): Nine Months Ended Beginning balance $ 116,174 Investment in installment notes 14,042 Principal payments and payoffs from customers (6,721 ) Principal reduction from repossessed homes (5,296 ) Total activity 2,025 Ending balance $ 118,199 Allowance for Losses for Installment Notes Receivable The following table sets forth the allowance change for the installment notes receivable as follows (in thousands): Nine Months Ended Beginning balance $ (377 ) Lower of cost or market write-downs 522 Increase to reserve balance (761 ) Total activity (239 ) Ending balance $ (616 ) Other Receivables As of September 30, 2018 , other receivables were comprised of amounts due from: residents for rent and water and sewer usage of $7.9 million (net of allowance of $1.8 million ); home sale proceeds of $19.8 million ; and insurance and other receivables of $22.4 million . As of December 31, 2017 , other receivables were comprised of amounts due from: residents for rent and water and sewer usage of $7.0 million (net of allowance of $1.5 million ); home sale proceeds of $13.8 million ; and insurance and other receivables of $26.9 million .

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets Disclosure [Text Block]	Intangible Assets Our intangible assets include ground leases, in-place leases, franchise agreements and other intangible assets. These intangible assets are recorded in Other assets, net on the Consolidated Balance Sheets. In June 2018, we acquired 50 percent of a land parcel that was previously subject to a ground lease at one of our California communities for $8.0 million. As a result of the transaction, we wrote off $1.1 million of the gross carrying amount of the ground lease intangible and $0.3 million of the related accumulated amortization. The $0.8 million net write off is included within the Property operating and maintenance expenses in our Consolidated Statements of Operations for the three months ended June 30, 2018. The gross carrying amounts, and accumulated amortization are as follows (in thousands): September 30, 2018 December 31, 2017 Intangible Asset Useful Life Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Ground leases 8-57 years $ 31,060 $ (1,755 ) $ 32,165 $ (1,409 ) In-place leases 7 years 103,598 (55,881 ) 100,843 (45,576 ) Franchise agreements and other intangible assets 7-15 years 16,521 (2,190 ) 1,880 (1,451 ) Total $ 151,179 $ (59,826 ) $ 134,888 $ (48,436 ) Total amortization expenses related to the intangible assets are as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Intangible Asset 2018 2017 2018 2017 Ground leases $ 188 $ 257 $ 633 $ 771 In-place leases 3,320 3,478 10,305 10,322 Franchise agreements and other intangible assets 717 19 755 277 Total $ 4,225 $ 3,754 $ 11,693 $ 11,370 We anticipate amortization expense for our intangible assets to be as follows for the next five years (in thousands): Year Remainder of 2018 2019 2020 2021 2022 Estimated expense $ 4,055 $ 15,960 $ 14,232 $ 13,840 $ 9,239

Investment In Affiliates

Investment In Affiliates	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investment In Affiliates	Investment in Affiliates GTSC LLC ( “GTSC” ) In February 2018, the Company became a noncontrolling member of GTSC. GTSC engages in acquiring, holding and selling loans secured, directly or indirectly, by manufactured homes located in communities of Sun Communities. At September 30, 2018 , we had a 40 percent ownership interest in GTSC. The remaining 60 percent interest is owned by an unrelated third-party. We account for our interest in GTSC under the equity method of accounting as prescribed by FASB ASC Topic 323 “ Investments - Equity Method and Joint Ventures.” Based on the power and economics criteria under the variable interest entity (“VIE”) model in ASC 810, we are not the primary beneficiary of GTSC. During the three and nine months ended September 30, 2018 , there was $0.1 million net gain in Brokerage commissions and other revenues, net respectively on the Consolidated Statement of Operations related to our ownership interest. Our investment in GTSC as of September 30, 2018 , is $19.9 million and recorded within Other assets, net on the Consolidated Balance Sheet.

Consolidated Variable Interest

Consolidated Variable Interest Entities	9 Months Ended
	Sep. 30, 2018
DisclosureofVariableInterestEntities [Abstract]
Consolidated Variable Interest Entities	Consolidated Variable Interest Entities Effective June 1, 2018, the Company acquired a majority interest in Sun NG RV Resorts LLC (“Sun NG Resorts”), which is comprised of ten RV resorts and one ground up RV development with 2,700 RV sites and an additional 940 sites available for development. The Company purchased an 80 percent interest in Sun NG Resorts for $ 61.6 million through Sun NG LLC; the remaining 20 percent interest of $ 15.4 million is held by NG Sun LLC, an unrelated third-party. Sun paid additional consideration of $ 123.3 million, consisting of a $ 1.8 million preferred equity investment and a $ 121.5 million temporary loan to Sun NG Resorts. We consolidate Sun NG Resorts under the guidance set forth in FASB ASC Topic 810 “Consolidation.” We concluded that Sun NG Resorts is a variable interest entity where we are the primary beneficiary, as we have power to direct the significant activities, absorb the significant losses and receive the significant benefits from the entity. Refer to Note 3, “Real Estate Acquisitions,” Note 9, “Debt and Lines of Credit,” and Note 10, “Equity and Mezzanine Securities” for additional information. We consolidate Rudgate Village SPE, LLC; Rudgate Clinton SPE, LLC; and Rudgate Clinton Estates SPE, LLC (collectively, “Rudgate”) as a VIE. We evaluated our arrangement with this property under the guidance set forth in FASB ASC Topic 810 “ Consolidation. ” We concluded that Rudgate qualified as a VIE where we are the primary beneficiary, as we have power to direct the significant activities, absorb the significant losses and receive the significant benefits from the entity. The following table summarizes the assets and liabilities included in our Consolidated Balance Sheets after eliminations (in thousands): September 30, 2018 December 31, 2017 ASSETS Investment property, net $ 300,693 $ 50,193 Other assets, net 20,655 1,659 TOTAL ASSETS $ 321,348 $ 51,852 LIABILITIES AND STOCKHOLDERS’ EQUITY Debt $ 44,426 $ 41,970 Preferred Equity - Sun NG Resorts - mandatorily redeemable 35,277 — Other liabilities 7,434 1,468 TOTAL LIABILITIES 87,137 43,438 Equity Interests - NG Sun LLC 21,976 — Noncontrolling interests 7,544 4,285 TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY $ 116,657 $ 47,723 Investment property, net and other assets, net related to the consolidated VIEs comprised approximately 4.8 percent and 0.8 percent of our consolidated total assets at September 30, 2018 and December 31, 2017 , respectively. Debt, Preferred Equity and other liabilities comprised approximately 2.6 percent and 1.2 percent of our consolidated total liabilities at September 30, 2018 and December 31, 2017 , respectively. Equity Interests and Noncontrolling interests related to the consolidated VIEs, on an absolute basis, comprised less than 1.0 percent of our consolidated total equity at September 30, 2018 and at December 31, 2017 .

Debt And Lines Of Credit

Debt And Lines Of Credit	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt and Lines of Credit The following table sets forth certain information regarding debt including premiums, discounts and deferred financing costs (in thousands): Carrying Amount Weighted Average Years to Maturity Weighted Average Interest Rates September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Collateralized term loans - Life Companies $ 1,253,935 $ 1,044,246 14.4 13.9 4.0 % 3.9 % Collateralized term loans - FNMA 775,383 1,026,014 5.4 5.6 4.4 % 4.4 % Collateralized term loans - CMBS 407,778 410,747 4.3 5.0 5.1 % 5.1 % Collateralized term loans - FMCC 382,129 386,349 6.1 6.9 3.9 % 3.9 % Secured borrowings 113,089 129,182 14.6 15.3 10.0 % 10.0 % Lines of credit — 41,257 0.0 3.1 — % 2.8 % Preferred Equity - Sun NG Resorts - mandatorily redeemable 35,277 — 4.0 - 6.0 % — % Preferred OP units - mandatorily redeemable 37,338 41,443 4.9 5.0 6.6 % 6.7 % Total debt $ 3,004,929 $ 3,079,238 9.4 8.9 4.5 % 4.5 % Collateralized Term Loans During the three months ended September 30, 2018, we entered into a $228.0 million collateralized term loan with a 4.10 percent fixed rate and a 20 -year term. During the three months ended September 30, 2018, we repaid one collateralized term loan of $30.5 million with an interest rate of 6.34 percent , releasing one encumbered community, which was due to mature March 1, 2019. We recognized a loss on extinguishment of debt of $0.3 million as a result of the repayment transaction in our Consolidated Statement of Operations. During the three months ended June 30, 2018 we repaid three collateralized term loans totaling $177.7 million with a weighted average interest rate of 4.53 percent, releasing 11 encumbered communities. One loan was due to mature on August 1, 2018 and two loans were due to mature on May 1, 2023. We recognized a loss on extinguishment of debt of $1.5 million as a result of the repayment transaction. During the three months ended March 31, 2018, we repaid four collateralized term loans totaling $24.4 million with a weighted average interest rate of 6.36 percent , releasing three encumbered communities. The loans were due to mature on March 1, 2019. We recognized a loss on extinguishment of debt of $0.2 million as a result of the repayment transactions. In December 2017, we defeased a $38.6 million collateralized term loan with a 5.25 percent fixed interest rate that was due to mature on June 1, 2022. As a result of the transaction we recognized a loss on extinguishment of debt of $5.2 million in our Consolidated Statements of Operations. Concurrent with the defeasance, we entered into a new $100.0 million collateralized term loan, encumbered by the same property, with a 4.25 percent fixed rate of interest and 30 -year term. In September 2017, in connection with the Ocean West acquisition, we assumed a $4.6 million collateralized term loan with Fannie Mae, with an interest rate of 4.34 percent and a remaining term of 9.8 years. In June 2017, we entered into a $77.0 million collateralized term loan which bears interest at a rate of 4.16 percent amortizing over a 25 -year term. We also repaid a $3.9 million collateralized term loan with an interest rate of 6.54 percent that was due to mature on August 31, 2017. As a result of the repayment transaction, we recognized a loss on extinguishment of debt of $0.3 million in our Consolidated Statements of Operations. During the first quarter of 2017, we defeased an $18.9 million collateralized term loan with an interest rate of 6.49 percent that was due to mature on August 1, 2017, releasing one encumbered community. As a result of the transaction, we recognized a loss on extinguishment of debt of $0.5 million in our Consolidated Statements of Operations. In addition, we repaid a $10.0 million collateralized term loan with an interest rate of 5.57 percent that was due to mature on May 1, 2017, releasing an additional encumbered community. The collateralized term loans totaling $2.8 billion as of September 30, 2018 , are secured by 185 properties comprised of 72,620 sites representing approximately $3.2 billion of net book value. Secured Borrowing See Note 4 , “Collateralized Receivables and Transfers of Financial Assets,” for information regarding our collateralized receivables and secured borrowing transactions. Preferred OP Units Preferred OP units at September 30, 2018 and December 31, 2017 include $34.7 million of Aspen preferred OP units issued by the Operating Partnership. As of September 30, 2018 , these units are convertible indirectly into 447,674 shares of our common stock. Subject to certain limitations, at any time prior to January 1, 2024, the holder of each Aspen preferred OP unit at its option may convert such Aspen preferred OP unit into: (a) if the market price of our common stock is $68.00 per share or less, 0.397 common OP units; or (b) if the market price of our common stock is greater than $68.00 per share, the number of common OP units is determined by dividing (i) the sum of (A) $27.00 plus (B) 25 percent of the amount by which the market price of our common stock exceeds $68.00 per share, by (ii) the per share market price of our common stock. The current preferred distribution rate is 6.5 percent . On January 2, 2024, we are required to redeem all Aspen preferred OP units that have not been converted to common OP units. Preferred OP units also include $2.7 million and $6.7 million at September 30, 2018 and December 31, 2017 , respectively, of Series B-3 preferred OP units, which are not convertible. During the nine months ended September 30, 2018 , we redeemed 41,051 of the Series B-3 preferred OP units at an average redemption price per unit, which included accrued and unpaid distributions, of $100.065753 . In the aggregate, we paid $4.1 million to redeem these units. Subject to certain limitations, (a) during the 90-day period beginning on each of the tenth through fifteenth anniversaries of the issue date of the applicable Series B-3 preferred OP units, (b) at any time after the fifteenth anniversary of the issue date of the applicable Series B-3 preferred OP units, or (c) after our receipt of notice of the death of the electing holder of a Series B-3 preferred OP unit, each holder of Series B-3 preferred OP units may require us to redeem such holder's Series B-3 preferred OP units at the redemption price of $100.00 per unit. In addition, at any time after the fifteenth anniversary of the issue date of the applicable Series B-3 preferred OP units we may redeem, at our option, all of the Series B-3 preferred OP units of any holder thereof at the redemption price of $100.00 per unit. Preferred Equity - Sun NG Resorts - mandatorily redeemable In June 2018, in connection with the investment in Sun NG Resorts, $35.3 million of mandatorily redeemable Preferred Equity (“Preferred Equity - Sun NG Resorts”) was purchased by unrelated third parties. The Preferred Equity - Sun NG Resorts carries a preferred rate of return of 6.0 percent per annum. The Preferred Equity - Sun NG Resorts has a seven -year term and can be redeemed in the fourth quarter of 2022 at the holders’ option. The Preferred Equity - Sun NG Resorts as of September 30, 2018 was $35.3 million . Refer to Note 3, “Real Estate Acquisitions,” Note 8, “Consolidated Variable Interest Entities,” and Note 10, “Equity and Mezzanine Securities” for additional information. Lines of Credit In April 2017, we amended and restated our credit agreement (the “A&R Credit Agreement”) with Citibank, N.A. (“Citibank”) and certain other lenders. Pursuant to the A&R Credit Agreement, we entered into a senior revolving credit facility with Citibank and certain other lenders in the amount of $650.0 million , comprised of a $550.0 million revolving loan and a $100.0 million term loan (the “A&R Facility”). We repaid the term loan in full on September 7, 2018.The A&R Credit Agreement has a four-year term ending April 25, 2021 , which can be extended for two additional six-month periods at our option, subject to the satisfaction of certain conditions as defined in the credit agreement. The A&R Credit Agreement also provides for, subject to the satisfaction of certain conditions, additional commitments in an amount not to exceed $350.0 million . If additional borrowings are made pursuant to any such additional commitments, the aggregate borrowing limit under the A&R Facility may be increased up to $900.0 million . The A&R Facility bears interest at a floating rate based on the Eurodollar rate plus a margin that is determined based on our leverage ratio calculated in accordance with the A&R Credit Agreement, which margin can range from 1.35 percent to 2.20 percent for the revolving loan and could range from 1.30 percent to 2.15 percent for the term loan. As of September 30, 2018 , the margin based on our leverage ratio was 1.35 percent and 1.30 percent on the revolving and term loans, respectively. We had no borrowings on the revolving loan and no borrowings on the term loan as of September 30, 2018 . The A&R Facility provides us with the ability to issue letters of credit. Our issuance of letters of credit does not increase our borrowings outstanding under our line of credit, but does reduce the borrowing amount available. At September 30, 2018 and December 31, 2017 , approximately $4.2 million and $1.3 million , respectively, of availability was used to back standby letters of credit. We have a $12.0 million manufactured home floor plan facility renewable indefinitely until our lender provides us at least a twelve month notice of their intent to terminate the agreement. The interest rate is 100 basis points over the greater of the prime rate as quoted in the Wall Street Journal on the first business day of each month or 6.0 percent. At September 30, 2018 , the effective interest rate was 7.0 percent . The outstanding balance was zero as of September 30, 2018 and $4.0 million as of December 31, 2017 . Covenants Pursuant to the terms of the A&R Facility, we are subject to various financial and other covenants. The most restrictive of our debt agreements place limitations on secured borrowings and contain minimum fixed charge coverage, leverage, distribution, and net worth requirements. At September 30, 2018 , we were in compliance with all covenants. In addition, certain of our subsidiary borrowers own properties that secure loans. These subsidiaries are consolidated within our accompanying Consolidated Financial Statements, however, each of these subsidiaries’ assets and credit are not available to satisfy the debts and other obligations of the Company, any of its other subsidiaries or any other person or entity.

Equity and Mezzanine Securities

Equity and Mezzanine Securities	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Equity and Mezzanine Securities	Equity and Mezzanine Securities Public Equity Offerings In September 2018, we closed an underwritten registered public offering of 5,060,000 shares of common stock. Proceeds from the offering were $499.9 million after deducting expenses related to the offering. We used the net proceeds of this offering to repay borrowings under the revolving loan and the term loan under our senior credit facility. The Company intends to use the remaining net proceeds of this offering to fund possible future acquisitions and for working capital and general corporate purposes. In May 2017, we closed an underwritten registered public offering of 4,830,000 shares of common stock. Proceeds from the offering were $408.9 million after deducting expenses related to the offering, which were used to repay borrowings outstanding under the revolving loan under our A&R Facility, fund acquisitions, working capital and general corporate purposes. At the Market Offering Sales Agreement In July 2017, we entered into a new at the market offering sales agreement (the “Sales Agreement”) with BMO Capital Markets Corp., Merrill Lynch, Pierce, Fenner & Smith Incorporated, Citigroup Global Markets Inc., Robert W. Baird & Co. Incorporated, Fifth Third Securities, Inc., RBC Capital Markets, LLC, BTIG, LLC, Jefferies LLC, Credit Suisse Securities (USA) LLC and Samuel A. Ramirez & Company, Inc. (each, a “Sales Agent;” collectively, the “Sales Agents”), whereby we may offer and sell shares of our common stock, having an aggregate offering price of up to $450.0 million , from time to time through the Sales Agents. The Sales Agents are entitled to compensation in an agreed amount not to exceed 2.0 percent of the gross price per share for any shares sold from time to time under the Sales Agreement. Through September 30, 2018 , we have sold shares of our common stock for gross proceeds of $163.8 million under the Sales Agreement. Issuances of common stock under the Sales Agreement during 2018 were as follows: Year to Date Common Stock Issued Weighted Average Sales Price Net Proceeds (in Millions) September 30, 2018 1,407,215 $ 95.02 $ 132.0 Equity Interests - NG Sun LLC In June 2018, in connection with the investment in Sun NG Resorts, unrelated third parties purchased $6.5 million of Series B preferred equity interests and $15.4 million of common equity interest (herein jointly referred to as “Equity Interest - NG Sun LLC”). The Series B preferred equity interests carry a preferred return at a rate that, at any time, is equal to the interest rate on Sun NG Resorts indebtedness at such time. The current rate of return is 5.0 percent. The Equity Interests - NG Sun LLC do not have a fixed maturity date and can be redeemed in the fourth quarter of 2022 at the holders option. Sun NG LLC, our subsidiary, has the right during certain periods each year, with or without cause, or for cause at any time, to elect to buy NG Sun LLC’s interest. During a limited period in 2022, NG Sun LLC has the right to put its interest to Sun NG LLC. If either party exercises their option, the property management agreement will be terminated and the Company is required to purchase the remaining interests of NG Sun LLC and the property management agreement at fair value. Refer to Note 3, “Real Estate Acquisitions,” Note 8, “Consolidated Variable Interest Entities,” and Note 9, “Debt and Lines of Credit” for additional information. Issuance of Common Stock and Common OP Units In July 2017, we issued 298,900 shares of common stock totaling $26.4 million in connection with the acquisition of Pismo Dunes. In June 2017, we issued a total of 23,311 common OP units for total consideration of $2.0 million in connection with acquisition activity during the three months ended June 30, 2017. Conversions Subject to certain limitations, holders can convert certain series of stock and OP units to shares of our common stock at any time. Below is the activity of conversions during the nine months ended September 30, 2018 and 2017 : Nine Months Ended Nine Months Ended Series Conversion Rate Units/Shares Converted Common Stock Units/Shares Converted Common Stock Common OP unit 1 16,908 16,908 25,238 25,238 Series A-1 preferred OP unit 2.439 13,100 31,948 18,319 44,676 Series A-4 preferred OP unit 0.4444 13,765 6,116 9,000 3,996 Series A-4 preferred stock 0.4444 22,576 10,033 158,036 70,238 Series C preferred OP unit 1.11 1,919 2,130 16,806 18,651 Cash Distributions Cash Distributions for the three months ended September 30, 2018 were as follows: Cash Distributions Record Date Payment Date Distribution per Share Total Distribution (thousands) Common Stock, Common OP units and Restricted Stock 9/28/2018 10/15/2018 $ 0.71 $ 63,250 Series A-4 Preferred Stock 9/14/2018 10/1/2018 $ 0.40625 $ 432 Redemptions If certain change of control transactions occur or if our common stock ceases to be listed or quoted on an exchange or quotation system, then at any time after November 26, 2019, we or the holders of shares of Series A-4 preferred stock and Series A-4 preferred OP units may cause all or any of those shares or units to be redeemed for cash at a redemption price equal to the sum of (i) the greater of (x) the amount that the redeemed shares of Series A-4 preferred stock and Series A-4 preferred OP units would have received in such transaction if they had been converted into shares of our common stock immediately prior to such transaction, or (y) $25.00 per share, plus (ii) any accrued and unpaid distributions thereon to, but not including, the redemption date. In November 2017, we redeemed all of the outstanding shares of our 7.125% Series A Cumulative Redeemable Preferred Stock. Holders received a cash payment of $25.14349 per share which included accrued and unpaid dividends. In the aggregate, we paid $85.5 million to redeem all of the 3,400,000 outstanding shares. In June 2017, we redeemed 438,448 shares of Series A-4 Preferred Stock and 200,000 shares of Series A-4 preferred OP units from Green Courte Real Estate Partners III, LLC, GCP Fund III REIT LLC and GCP Fund III Ancillary Holding, LLC (collectively, the “Green Courte Entities”) for total consideration of $24.7 million . Accrued dividends totaling $0.2 million were also paid in connection with the redemptions. The Green Courte Entities were the sellers of the American Land Lease portfolio which we acquired in 2014 and 2015. Repurchase Program In November 2004, our Board of Directors authorized us to repurchase up to 1,000,000 shares of our common stock. We have 400,000 common shares remaining in the repurchase program as of September 30, 2018. No common shares were repurchased during the nine months ended September 30, 2018 or 2017 . There is no expiration date specified for the buyback program.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2018
Share-based Compensation [Abstract]
Share-Based Compensation	Share-Based Compensation As of September 30, 2018 , we had two share-based compensation plans; the Sun Communities, Inc. 2015 Equity Incentive Plan (“2015 Equity Incentive Plan”) and the First Amended and Restated 2004 Non-Employee Director Option Plan (“2004 Non-Employee Director Option Plan”). We believe granting equity awards will provide certain executives, key employees and directors additional incentives to promote our financial success, and promote employee and director retention by providing an opportunity to acquire or increase the direct proprietary interest of those individuals in our operations and future. The following table shows details on grants of equity awards during the nine months ended September 30, 2018 : Grant Period Type Plan Shares Granted Grant Date Fair Value Per Share Vesting Type Vesting Anniversary Percentage 2018 Key Employees 2015 Equity Incentive Plan 16,500 $ 88.30 (1) Time Based 2nd 35.0 % 3rd 35.0 % 4th 20.0 % 5th 5.0 % 6th 5.0 % 2018 Key Employees 2015 Equity Incentive Plan 47,600 $ 86.22 (1) Time Based 20.0% annually over 5 years 2018 Executive Officers 2015 Equity Incentive Plan 60,000 $ 87.24 (2) Time Based 20.0% annually over 5 years 2018 Executive Officers 2015 Equity Incentive Plan 90,000 $ 65.24 (3) Market Condition 3rd 100.0 % 2018 Directors 2004 Non-Employee Director Option Plan 16,800 $ 85.28 (2) Time Based 3rd 100.0 % (1) The fair value of the grants were determined by using the average closing price of our common stock on the dates the shares were issued. (2) The fair value of the grants were determined by using the closing price of our common stock on the dates the shares were issued. (3) Share-based compensation for restricted stock awards with market conditions is measured based on an estimate of shares expected to vest. We estimate the fair value of share-based compensation for restricted stock with market conditions using a Monte Carlo simulation. At the grant date ,our common stock price was $87.24 . Based on the Monte Carlo simulation we expect 74.8% of the 90,000 shares to vest. Vesting The vesting requirements for 202,368 restricted shares granted to our executives, directors and employees were satisfied during the nine months ended September 30, 2018 .

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting We group our operating segments into reportable segments that provide similar products and services. Each operating segment has discrete financial information evaluated regularly by our chief operating decision maker in evaluating and assessing performance. We have two reportable segments: (i) Real Property Operations and (ii) Home Sales and Rentals. The Real Property Operations segment owns, operates, develops, or has an interest in a portfolio of MH and RV communities, and is in the business of acquiring, operating, and expanding MH and RV communities. The Home Sales and Rentals segment offers MH and RV park model sales and leasing services to tenants and prospective tenants of our communities. Transactions between our segments are eliminated in consolidation. Transient RV revenue is included in the Real Property Operations segment revenues and is expected to approximate $107.6 million annually. Transient RV revenue was recognized 20.4 percent, 20.1 percent, and 42.0 percent in the first, second, and third quarters, respectively, and is expected to be 17.5 percent in the fourth quarter. Transient revenue was $78.0 million for the year ended December 31, 2017. We recognized 27.2 percent in the first quarter, 20.1 percent in the second quarter, 36.9 percent in the third quarter, and 15.8 percent in the fourth quarter. A presentation of segment financial information is summarized as follows (in thousands): Three Months Ended September 30, 2018 Three Months Ended September 30, 2017 Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated Revenues $ 257,215 $ 59,720 $ 316,935 $ 215,280 $ 45,954 $ 261,234 Operating expenses/Cost of sales 101,258 39,831 141,089 82,388 31,869 114,257 Net operating income/Gross profit 155,957 19,889 175,846 132,892 14,085 146,977 Adjustments to arrive at net income / (loss): Interest and other revenues, net 6,603 — 6,603 7,011 — 7,011 Home selling expenses — (4,043 ) (4,043 ) — (3,290 ) (3,290 ) General and administrative (17,187 ) (2,940 ) (20,127 ) (15,677 ) (2,497 ) (18,174 ) Transaction costs (24 ) — (24 ) (2,153 ) (14 ) (2,167 ) Depreciation and amortization (54,305 ) (17,677 ) (71,982 ) (48,624 ) (15,608 ) (64,232 ) Loss on extinguishment of debt (939 ) — (939 ) — — — Interest (33,516 ) (5 ) (33,521 ) (32,082 ) (3 ) (32,085 ) Interest on mandatorily redeemable preferred OP units / equity (1,142 ) — (1,142 ) (790 ) — (790 ) Catastrophic weather related charges, net (173 ) — (173 ) (7,718 ) (38 ) (7,756 ) Other income, net 1,230 1 1,231 3,345 — 3,345 Current tax (expense) / benefit (135 ) (78 ) (213 ) 210 (172 ) 38 Deferred tax benefit 199 — 199 81 — 81 Net income / (loss) 56,568 (4,853 ) 51,715 36,495 (7,537 ) 28,958 Less: Preferred return to preferred OP units 1,152 — 1,152 1,112 — 1,112 Less: Amounts attributable to noncontrolling interests 4,304 (233 ) 4,071 2,169 (393 ) 1,776 Net income / (loss) attributable to Sun Communities, Inc. 51,112 (4,620 ) 46,492 33,214 (7,144 ) 26,070 Less: Preferred stock distributions 432 — 432 1,955 — 1,955 Net income / (loss) attributable to Sun Communities, Inc. common stockholders $ 50,680 $ (4,620 ) $ 46,060 $ 31,259 $ (7,144 ) $ 24,115 Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated Revenues $ 671,695 $ 162,205 $ 833,900 592,864 129,093 $ 721,957 Operating expenses/Cost of sales 253,009 107,772 360,781 221,178 84,820 305,998 Net operating income/Gross profit 418,686 54,433 473,119 371,686 44,273 415,959 Adjustments to arrive at net income / (loss): Interest and other revenues, net 18,980 — 18,980 18,587 — 18,587 Home selling expenses — (11,319 ) (11,319 ) — (9,391 ) (9,391 ) General and administrative (52,966 ) (8,466 ) (61,432 ) (49,082 ) (6,830 ) (55,912 ) Transaction costs (138 ) — (138 ) (7,001 ) 11 (6,990 ) Depreciation and amortization (155,624 ) (50,568 ) (206,192 ) (144,143 ) (45,576 ) (189,719 ) Loss on extinguishment of debt (2,657 ) — (2,657 ) (759 ) — (759 ) Interest (96,904 ) (15 ) (96,919 ) (95,754 ) (11 ) (95,765 ) Interest on mandatorily redeemable preferred OP units / equity (2,551 ) — (2,551 ) (2,361 ) — (2,361 ) Catastrophic weather related charges, net 2,206 (219 ) 1,987 (8,075 ) (49 ) (8,124 ) Other (expense) / income, net (3,215 ) 1 (3,214 ) 5,341 (1 ) 5,340 Current tax (expense) / income (366 ) (246 ) (612 ) 145 (278 ) (133 ) Deferred tax benefit 434 — 434 745 — 745 Net income / (loss) 125,885 (16,399 ) 109,486 89,329 (17,852 ) 71,477 Less: Preferred return to preferred OP units 3,335 — 3,335 3,482 — 3,482 Less: Amounts attributable to noncontrolling interests 9,204 (812 ) 8,392 5,148 (969 ) 4,179 Net income / (loss) attributable to Sun Communities, Inc. 113,346 (15,587 ) 97,759 80,699 (16,883 ) 63,816 Less: Preferred stock distributions 1,305 — 1,305 6,233 — 6,233 Net income / (loss) attributable to Sun Communities, Inc. common stockholders $ 112,041 $ (15,587 ) $ 96,454 $ 74,466 $ (16,883 ) $ 57,583 September 30, 2018 December 31, 2017 Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated Identifiable assets: Investment property, net $ 5,534,397 $ 519,580 $ 6,053,977 $ 5,172,521 $ 472,833 $ 5,645,354 Cash and cash equivalents 86,857 26,699 113,556 (7,649 ) 17,776 10,127 Inventory of manufactured homes — 41,030 41,030 — 30,430 30,430 Notes and other receivables, net 149,564 18,134 167,698 149,798 13,698 163,496 Collateralized receivables, net 112,228 — 112,228 128,246 — 128,246 Other assets, net 138,451 26,786 165,237 130,455 3,849 134,304 Total assets $ 6,021,497 $ 632,229 $ 6,653,726 $ 5,573,371 $ 538,586 $ 6,111,957

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We have elected to be taxed as a real estate investment trust (“REIT”) pursuant to Section 856(c) of the Internal Revenue Code of 1986, as amended (“Code”). In order for us to qualify as a REIT, at least 95 percent of our gross income in any year must be derived from qualifying sources. In addition, a REIT must distribute annually at least 90 percent of its REIT taxable income (calculated without any deduction for dividends paid and excluding capital gain) to its stockholders and meet other tests. Qualification as a REIT involves the satisfaction of numerous requirements (on an annual and quarterly basis) established under highly technical and complex Code provisions for which there are limited judicial or administrative interpretations, and involves the determination of various factual matters and circumstances not entirely within our control. In addition, frequent changes occur in the area of REIT taxation which requires us to continually monitor our tax status. We analyzed the various REIT tests and confirmed that we continued to qualify as a REIT for the quarter ended September 30, 2018 . As a REIT, we generally will not be subject to United States (“U.S.”) federal income taxes at the corporate level on the ordinary taxable income we distribute to our stockholders as dividends. If we fail to qualify as a REIT in any taxable year, our taxable income could be subject to U.S. federal income tax at regular corporate rates (including any applicable alternative minimum tax). Even if we qualify as a REIT, we may be subject to certain state and local income taxes as well as U.S. federal income and excise taxes on our undistributed income. In addition, taxable income from non-REIT activities managed through taxable REIT subsidiaries is subject to federal, state, and local income taxes. The Company is also subject to local income taxes in Canada as a result of the acquisition of Carefree in 2016. We do not provide for withholding taxes on our undistributed earnings from our Canadian subsidiaries as they are reinvested and will continue to be reinvested indefinitely outside of the U.S. Our taxable REIT subsidiaries are subject to U.S. federal income taxes as well as state and local income and franchise taxes. In addition, our Canadian subsidiaries are subject to income tax in Canada. Deferred tax assets and liabilities reflect the impact of temporary differences between the amounts of assets and liabilities for financial reporting purposes and the bases of such assets and liabilities as measured by tax laws. Deferred tax assets are reduced, if necessary, by a valuation allowance to the amount where realization is more likely than not assured after considering all available evidence. Our temporary differences primarily relate to net operating loss carryforwards, depreciation and basis differences between tax and U.S. GAAP on our Canadian investments. Generally, full valuation allowances are recorded against almost all U.S. federal deferred tax assets. Deferred tax liabilities of $21.3 million for Canadian entities have been recorded in relation to corporate entities and included in “Other liabilities” in our Consolidated Balance Sheets as of September 30, 2018 . There are no U.S. federal deferred tax assets or liabilities included in our Consolidated Balance sheets as of September 30, 2018 and December 31, 2017. Our deferred tax assets that have a full valuation allowance relate to our taxable REIT subsidiary (“TRS”) business which has historically produced losses. While at this time, we have evidence that our TRS business may shift to profitability, we have not achieved a sustained historical profitability that would, in our judgment, support a release of the full valuation allowance at September 30, 2018. We had no unrecognized tax benefits as of September 30, 2018 and 2017 . We do not expect significant changes in tax positions that would result in unrecognized tax benefits within one year of September 30, 2018 . We recorded a current tax expense for federal, state, and Canadian income taxes of $0.2 million for the three months ended September 30, 2018 and a current tax benefit of approximately $0.1 million for the three months ended September 30, 2017 . For the nine months ended September 30, 2018 and 2017, we recorded a current tax expense of $0.6 million and $0.1 million , respectively. For the three months ended September 30, 2018 and 2017, we recorded a deferred tax benefit of $0.2 million and $0.1 million , respectively. For the nine months ended September 30, 2018 and 2017, we recorded a deferred tax benefit of $0.4 million and $0.7 million , respectively. In 2017, SHS underwent an audit by the Internal Revenue Service for the 2015 tax year. Upon conclusion of the audit in 2018, no adjustment was required.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share We have outstanding stock options, unvested restricted common shares, and Series A-4 Preferred Stock, and our Operating Partnership has: outstanding common OP units; Series A-1 preferred OP units; Series A-3 preferred OP units; Series A-4 preferred OP units; Series C preferred OP units; and Aspen preferred OP Units, which, if converted or exercised, may impact dilution. Computations of basic and diluted earnings per share were as follows (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2018 2017 2018 2017 Net income attributable to common stockholders $ 46,060 $ 24,115 $ 96,454 $ 57,583 Allocation to restricted stock awards (396 ) (189 ) (830 ) (461 ) Basic earnings: Net income attributable to common stockholders after allocation 45,664 23,926 95,624 57,122 Allocation to restricted stock awards 396 189 — 461 Diluted earnings: Net income attributable to common stockholders after allocation $ 46,060 $ 24,115 $ 95,624 $ 57,583 Denominator Weighted average common shares outstanding 81,599 78,369 80,022 75,234 Add: dilutive stock options 2 2 2 2 Add: dilutive restricted stock 480 437 — 610 Diluted weighted average common shares and securities 82,081 78,808 80,024 75,846 Earnings per share available to common stockholders after allocation: Basic $ 0.56 $ 0.31 $ 1.19 $ 0.76 Diluted $ 0.56 $ 0.31 $ 1.19 $ 0.76 We have excluded certain convertible securities from the computation of diluted earnings per share because the inclusion of these securities would have been anti-dilutive for the periods presented. The following table presents the outstanding securities that were excluded from the computation of diluted earnings per share as of September 30, 2018 and 2017 (in thousands): As of September 30, 2018 2017 Common OP units 2,729 2,757 Series A-1 preferred OP units 332 349 Series A-3 preferred OP units 40 40 Series A-4 preferred OP units 410 425 Series A-4 preferred stock 1,063 1,085 Series C preferred OP units 314 316 Aspen preferred OP units 1,284 1,284 Total securities 6,172 6,256

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Of Financial Instruments	Fair Value of Financial Instruments Our financial instruments consist primarily of cash and cash equivalents, accounts and notes receivable, accounts payable, derivative instruments, and debt. ASC Topic 820 “ Fair Value Measurements and Disclosures, ” requires disclosure regarding determination of fair value for assets and liabilities and establishes a hierarchy under which these assets and liabilities must be grouped, based on significant levels of observable or unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s market assumption. This hierarchy requires the use of observable market data when available. These two types of inputs have created the following fair value hierarchy: Level 1—Quoted unadjusted prices for identical instruments in active markets; Level 2—Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets; and Level 3—Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. We utilize fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. The following methods and assumptions were used in order to estimate the fair value of each class of financial instruments for which it is practicable to estimate that value: Installment Notes Receivable on Manufactured Homes The net carrying value of the installment notes receivable on manufactured homes estimates the fair value as the interest rates in the portfolio are comparable to current prevailing market rates (Level 2). Refer to Note 5 , “Notes and Other Receivables.” Long-Term Debt and Lines of Credit The fair value of long-term debt (excluding the secured borrowing) is based on the estimates of management and on rates currently quoted, rates currently prevailing for comparable loans, and instruments of comparable maturities (Level 2). Refer to Note 9 , “Debt and Lines of Credit.” Collateralized Receivables and Secured Borrowings The fair value of these financial instruments offset each other as our collateralized receivables represent a transfer of financial assets and the cash proceeds received from these transactions have been classified as a secured borrowing on the Consolidated Balance Sheets. The net carrying value of the collateralized receivables estimates the fair value as the interest rates in the portfolio are comparable to current prevailing market rates (Level 2). Refer to Note 4 , “Collateralized Receivables and Transfers of Financial Assets.” Financial Liabilities We estimate the fair value of our contingent consideration liability based on discounting of future cash flows using market interest rates and adjusting for non-performance risk over the remaining term of the liability (Level 2). Other Financial Instruments The carrying values of cash and cash equivalents, accounts receivable, and accounts payable approximate their fair market values due to the short-term nature of these instruments. The table below sets forth our financial assets and liabilities that required disclosure of fair value on a recurring basis as of September 30, 2018 . The table presents the carrying values and fair values of our financial instruments as of September 30, 2018 and December 31, 2017 , that were measured using the valuation techniques described above (in thousands). The table excludes other financial instruments such as cash and cash equivalents, accounts receivable, and accounts payable as the carrying values associated with these instruments approximate fair value since their maturities are less than one year. September 30, 2018 December 31, 2017 Financial assets Carrying Value Fair Value Carrying Value Fair Value Installment notes receivable on manufactured homes, net $ 117,583 $ 117,583 $ 115,797 $ 115,797 Collateralized receivables, net $ 112,228 $ 112,228 $ 128,246 $ 128,246 Financial liabilities Debt (excluding secured borrowings) $ 2,891,840 $ 2,798,537 $ 2,908,799 $ 2,726,770 Secured borrowings $ 113,089 $ 113,089 $ 129,182 $ 129,182 Lines of credit $ — $ — $ 41,257 $ 41,257 Other liabilities (contingent consideration) $ 7,261 $ 7,261 $ 6,976 $ 6,976

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recent Accounting Pronouncements - Adopted On January 1, 2018, we adopted ASU 2014-09 “ Revenue from Contracts with Customers (Topic 606). ” Refer to Note 2, “Revenue” for information regarding our adoption of this guidance. On January 1, 2018 we adopted ASU 2017-09 “Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting.” This update provided clarity and reduced both diversity in practice and cost and complexity when applying the guidance in Topic 718, Compensation - Stock Compensation, regarding a change to the terms or conditions of a share-based payment award. There was no initial impact that resulted from adoption of this guidance; it will be applied should a modification occur. On January 1, 2018, we adopted ASU 2017-01 “Business Combinations (Topic 805): Clarifying the Definition of a Business.” This update clarified the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. Under previous guidance, substantially all of our property acquisitions were accounted for as business combinations with identifiable assets and liabilities measured at fair value, and acquisition related costs expensed as incurred. With the adoption of ASU 2017-01, we expect that substantially all of our future property acquisitions will be accounted for as asset acquisitions. We allocate the purchase price of these properties on a relative fair value basis and capitalize direct acquisition related costs as part of the purchase price. Acquisitions costs that do not meet the criteria to be capitalized will be expensed as incurred and presented as General and administrative costs in our Consolidated Statements of Operations. On January 1, 2018, we adopted ASU 2016-18 “Statement of Cash Flows (Topic 230): Restricted Cash.” This update required inclusion of restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. Our restricted cash consists of amounts primarily held in deposit for tax, insurance and repair escrows held by lenders in accordance with certain debt agreements. Restricted cash is included as a component of Other assets, net on the Consolidated Balance Sheets. Changes in restricted cash are reported in our Consolidated Statements of Cash Flows as operating, investing or financing activities based on the nature of the underlying activity. The following table reconciles our beginning-of-period and end-of-period balances of cash, cash equivalents and restricted cash for the periods shown (in thousands): September 30, 2018 December 31, 2017 September 30, 2017 December 31, 2016 Cash and cash equivalents $ 113,556 $ 10,127 $ 137,448 $ 8,164 Restricted cash 15,538 13,382 19,943 17,149 Cash, cash equivalents and restricted cash $ 129,094 $ 23,509 $ 157,391 $ 25,313 Recent Accounting Pronouncements - Not Yet Adopted In June 2016, the FASB issued ASU 2016-13 “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ” This update replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in this update are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are in the initial phases of evaluating how this guidance will impact our accounting policies regarding assessment of, and allowance for, loan losses. In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842).” The core principle of this update is that a lessee should recognize the right of use (“ROU”) assets and liabilities in the Consolidated Balance Sheet that arise from lease agreements. The ROU asset represents our right to use an underlying asset for the term of the lease and the lease liability represents our obligation to make lease payments arising for the agreements. The accounting by a lessor is largely unchanged from that applied under previous GAAP. This update also requires significant additional disclosures about the amount, timing and uncertainty of cash flows from leases. The amendments in this update are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We will adopt the amendment in the first quarter 2019 using the prospective approach. Our income from real property and rental home revenue streams is derived from rental agreements where we are the lessor. The new accounting standard narrowed the definition of initial direct costs which can be capitalized. The new standard defines initial direct costs as the incremental costs of signing a lease. Employee salaries, legal fees rendered prior to the execution of a lease, negotiation costs, advertising and other origination effort costs no longer meet the definition of initial direct costs. These costs will now be included in general and administrative costs in our Consolidated Statement of Operations. We are currently assessing the impact of our measurement of initial direct costs under the new standard definition. We are the lessee in other arrangements, primarily for our executive offices, ground leases at certain communities and certain equipment. For leases with a term greater than one year, a right of use asset and corresponding ROU liability are to be included on the Consolidated Balance Sheet. The ROU asset and liability is measured as the estimated present value of minimum lease payments at the commencement of the lease agreement and discounted by our incremental borrowing rate of a collateralized term loan. For existing leases the ROU asset and ROU liability will be measured at the remaining present value of the lease payments. The lease liability is amortized over the straight line method over the term of the lease agreement. Extension options on ROU assets are included if the option is reasonably certain to be exercised. Operating leases with a term of less than one year are recognized as a lease expense over the term of the lease, no asset or liability is recognized on the Consolidated Balance Sheet. Variable lease payments are excluded from the ROU asset and liability on the Consolidated Balance Sheet and are recognized in the period in which the obligation payment occurred and recognized as variable lease obligation payments on the Consolidated Statement of Operations. We are currently evaluating our inventory of such leases to determine which will require recognition of right of use assets, corresponding lease liabilities, and the related disclosure requirements thereto. We will elect certain practical expedients allowable by the ASU, including the expedient to forego separation of lease and non-lease component of lessee contracts, resulting in a gross-up effect on the balance sheet assets and liabilities. Additionally for all leases, we will elect the package of practical expedients, which permits the Company not to reassess expired or existing contracts containing a lease, the lease classification for expired or existing contracts, and measurement of initial direct costs for any existing leases. In August 2018, the FASB issued ASU 2018-15 “ Intangibles- Goodwill and Other- Internal-Use Software (Topic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract.” This update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal use software. The amendments in this update are effective for fiscal years beginning after December 15, 2020. Early adoption of the amendments in this update is permitted, including adoption in any interim period, for all entities. We are currently evaluating the potential impact of adoption of this standard on our consolidated financial statements.

Commitments And Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies Legal Proceedings We are involved in various legal proceedings arising in the ordinary course of business. All such proceedings, taken together, are not expected to have a material adverse impact on our results of operations or financial condition. Catastrophic Weather Related Estimates In September 2017, our communities in Florida and Georgia sustained damages from Hurricane Irma. The table below sets forth estimated losses (in millions). Future changes to estimated losses will be recognized in the period(s) in which they are determined. We maintain property, casualty, flood and business interruption insurance for our community portfolio, subject to customary deductibles and limits. The table below sets forth estimated insurance recoveries (in millions). Actual insurance recoveries could vary significantly from our estimates. Future changes to estimated insurance recoveries will be recognized in the period(s) in which they are determined. Nine Months Ended September 30, 2018 Total estimated insurance receivable - December 31, 2017 $ 23.7 Change in estimated insurance recoveries 8.9 Advances from insurer (16.4 ) Total estimated insurance receivable - September 30, 2018 $ 16.2 Changes in estimated insurance recoveries for damages during the nine months ended September 30, 2018 , were primarily the result of incremental invoices for which the total costs exceeded the applicable deductible. The change in estimated losses and changes in estimated insurance recoveries during the three and nine months ended September 30, 2018 , resulted in a net loss of $0.2 million and a net gain of $2.0 million , respectively to Catastrophic weather related charges, net in our Consolidated Statements of Operations. We are actively working with our insurer on claims for lost earnings and redevelopment costs greater than the asset impairment charge for the three Florida Keys communities. The three impaired Florida Keys communities will require redevelopment followed by a tenant lease-up period. As such, we currently cannot estimate a date when operating results will be restored to pre-hurricane levels. Our business interruption insurance policy provides for up to 60 months of coverage from the date of restoration.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Event	Subsequent Events In October 2018, we acquired a parcel of land in Austin, Texas for $ 4.2 million. The land parcel is an expansion for 220 MH development sites to our Oak Crest community. We have evaluated our Consolidated Financial Statements for subsequent events through the date that this Form 10-Q was issued.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables disaggregates our revenue by major source (in thousands): Three Months Ended Three Months Ended Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated REVENUE Income from real property $ 229,607 $ — $ 229,607 $ 198,263 $ — $ 198,263 Revenue from home sales — 46,131 46,131 — 33,197 33,197 Rental home revenue — 13,589 13,589 — 12,757 12,757 Ancillary revenues 27,608 — 27,608 17,017 — 17,017 Interest 5,256 — 5,256 5,920 — 5,920 Brokerage commissions and other revenues, net 1,347 — 1,347 1,091 — 1,091 Total revenue $ 263,818 $ 59,720 $ 323,538 $ 222,291 $ 45,954 $ 268,245 Nine Months Ended Nine Months Ended Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated REVENUE Income from real property $ 625,488 $ — $ 625,488 $ 560,778 $ — $ 560,778 Revenue from home sales — 122,248 122,248 — 91,319 91,319 Rental home revenue — 39,957 39,957 — 37,774 37,774 Ancillary revenues 46,207 — 46,207 32,086 — 32,086 Interest 15,849 — 15,849 15,609 — 15,609 Brokerage commissions and other revenues, net 3,131 — 3,131 2,978 — 2,978 Total revenue $ 690,675 $ 162,205 $ 852,880 $ 611,451 $ 129,093 $ 740,544

Real Estate Acquisitions (Table

Real Estate Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2018
Business Acquisition [Line Items]
Schedule of Purchase Price Allocation	The following table summarizes the amounts of assets acquired net of liabilities assumed at the acquisition date and the consideration paid for the acquisitions completed in 2017 (in thousands): At Acquisition Date Colony in the Wood Emerald Coast Lazy J Ranch Ocean West Caliente Sands Pismo Dunes Arbor Woods Sunset Lakes 49er Village Total Investment in property $ 31,818 $ 19,400 $ 13,938 $ 9,453 $ 8,640 $ 21,260 $ 15,725 $ 7,835 $ 12,890 $ 140,959 Notes receivable — — — — — — 23 — — 23 Inventory of manufactured homes — — 2 — 21 — 465 — — 488 In-place leases and other intangible assets 660 100 360 220 210 660 730 210 110 3,260 Total identifiable assets acquired net of liabilities assumed $ 32,478 $ 19,500 $ 14,300 $ 9,673 $ 8,871 $ 21,920 $ 16,943 $ 8,045 $ 13,000 $ 144,730 Consideration Cash $ 32,478 $ 19,500 $ 14,300 $ 5,081 $ 8,871 $ — $ 14,943 $ 8,045 $ 13,000 $ 116,218 Equity — — — — — 26,410 2,000 — — 28,410 Liabilities assumed — — — 4,592 — 510 — — — 5,102 Cash proceeds from seller — — — — — (5,000 ) — — — (5,000 ) Total consideration $ 32,478 $ 19,500 $ 14,300 $ 9,673 $ 8,871 $ 21,920 $ 16,943 $ 8,045 $ 13,000 $ 144,730 The following table summarizes the amounts of assets acquired net of liabilities assumed at the acquisition date and the consideration paid for the acquisitions completed in 2018 (in thousands): At Acquisition Date Archview Petoskey KOA Sands Sun NG Resorts Silver Creek Highway West Compass Total Investment in property $ 14,550 $ 9,000 $ 13,790 $ 240,649 $ 7,250 $ 36,500 $ 13,930 $ 335,669 In-place leases and other intangible assets — — 460 16,339 — — 70 16,869 Debt assumed — — — (3,120 ) — — — (3,120 ) Other liabilities, net — — — (11,990 ) — — — (11,990 ) Total identifiable assets acquired net of liabilities assumed $ 14,550 $ 9,000 $ 14,250 $ 241,878 $ 7,250 $ 36,500 $ 14,000 $ 337,428 Consideration Cash $ 14,550 $ 9,000 $ 14,250 $ 184,625 $ 7,250 $ 36,500 $ 14,000 $ 280,175 Preferred Equity - Sun NG Resorts — — — 35,277 — — — 35,277 Equity Interests - NG Sun LLC — — — 21,976 — — — 21,976 Total consideration $ 14,550 $ 9,000 $ 14,250 $ 241,878 $ 7,250 $ 36,500 $ 14,000 $ 337,428
Business Acquisition, Pro Forma Information	The total amount of revenues and net income included in the Consolidated Statements of Operations for the three and nine months ended September 30, 2018 related to the acquisitions completed in 2018 are set forth in the following table (in thousands): Three Months Ended Nine Months Ended (unaudited) (unaudited) Total revenues $ 26,317 $ 33,433 Net income $ 7,529 $ 11,356 The information presented below has been prepared for comparative purposes only and does not purport to be indicative of either future results of operations or the results of operations that would have actually occurred had the acquisition been consummated on January 1, 2017 (in thousands, except per-share data): Three Months Ended September 30, Nine Months Ended September 30, (unaudited) (unaudited) 2018 2017 2018 2017 Total revenues $ 325,504 $ 296,322 $ 861,193 $ 780,529 Net income attributable to Sun Communities, Inc. common stockholders $ 57,413 $ 42,987 $ 93,714 $ 68,378 Net income per share attributable to Sun Communities, Inc. common stockholders - basic $ 0.70 $ 0.55 $ 1.17 $ 0.91 Net income per share attributable to Sun Communities, Inc. common stockholders - diluted $ 0.70 $ 0.55 $ 1.17 $ 0.90
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	In 2018 we acquired the following communities: Community Name Type Sites Development Sites State Month Acquired Archview RV 114 50 UT August Petoskey KOA RV 210 — MI August The Sands RV and Golf Resort RV (Age Restricted) 507 — CA July Sun NG RV Resorts LLC (1) RV 2,700 940 Various June Silver Creek RV 264 176 MI June Highway West (Four Resorts) RV 536 — UT & OR June Compass RV RV 175 — FL May Total 4,506 1,166 (1) Refer to Note 8, “Consolidated Variable Interest Entities,” Note 9, “Debt and Lines of Credit,” and Note 10, “Equity and Mezzanine Securities” for additional information. In 2018, we acquired the following land for expansion / development: Name Location Type Expansion / Development Sites Cost (millions) Month Acquired Pecan Park Jacksonville, FL RV 158 $ 1.3 September Smith Creek Crossing Granby, CO MH 310 $ 0.9 September River Run Ranch Granby, CO MH / RV 1,144 $ 5.3 May Total 1,612 $ 7.5 In 2017, we acquired the following communities: Community Name Type Sites Development Sites State Month Acquired Colony in the Wood MH (Age Restricted) 383 — FL December Emerald Coast MH and RV 201 14 FL November Lazy J Ranch MH (Age Restricted) 220 — CA September Ocean West MH (Age Restricted) 130 4 CA September Caliente Sands MH (Age Restricted) 118 — CA September Pismo Dunes RV (Age Restricted) 331 — CA July Arbor Woods MH 458 — MI June Sunset Lakes RV 498 — IL May 49er Village RV 328 — CA March Total 2,667 18

Collateralized Receivables an_2

Collateralized Receivables and Transfers of Financial Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repurchase price percentage	Number of Payments Repurchase Percentage Fewer than or equal to 15 100 % Greater than 15 but fewer than 64 90 % Equal to or greater than 64 but fewer than 120 65 % 120 or more 50 %
Schedule of collateralized loans	Nine Months Ended Beginning balance $ 129,182 Principal payments and payoffs from our customers (9,386 ) Principal reduction from repurchased homes (6,707 ) Total activity (16,093 ) Ending balance $ 113,089
Collateralized Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for collateralized and installment notes receivable	The following table sets forth the allowance for the collateralized receivables as of September 30, 2018 (in thousands): Nine Months Ended Beginning balance $ (936 ) Lower of cost or market write-downs 587 Increase to reserve balance (512 ) Total activity 75 Ending balance $ (861 )

Notes And Other Receivables (Ta

Notes And Other Receivables (Tables)	9 Months Ended
	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Schedule of notes and other receivables	The following table sets forth certain information regarding notes and other receivables (in thousands): September 30, 2018 December 31, 2017 Installment notes receivable on manufactured homes, net $ 117,583 $ 115,797 Other receivables, net 50,115 47,699 Total notes and other receivables, net $ 167,698 $ 163,496
Schedule of Installment Notes Receivable	The change in the aggregate gross principal balance of the installment notes receivable is as follows (in thousands): Nine Months Ended Beginning balance $ 116,174 Investment in installment notes 14,042 Principal payments and payoffs from customers (6,721 ) Principal reduction from repossessed homes (5,296 ) Total activity 2,025 Ending balance $ 118,199
Installment Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for collateralized and installment notes receivable	The following table sets forth the allowance change for the installment notes receivable as follows (in thousands): Nine Months Ended Beginning balance $ (377 ) Lower of cost or market write-downs 522 Increase to reserve balance (761 ) Total activity (239 ) Ending balance $ (616 )

Intangible Assets Intangible As

Intangible Assets Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Finite-Lived Intangible Assets, Net [Abstract]
Schedule of Finite-Lived Intangible Assets	The gross carrying amounts, and accumulated amortization are as follows (in thousands): September 30, 2018 December 31, 2017 Intangible Asset Useful Life Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Ground leases 8-57 years $ 31,060 $ (1,755 ) $ 32,165 $ (1,409 ) In-place leases 7 years 103,598 (55,881 ) 100,843 (45,576 ) Franchise agreements and other intangible assets 7-15 years 16,521 (2,190 ) 1,880 (1,451 ) Total $ 151,179 $ (59,826 ) $ 134,888 $ (48,436 )
Schedule of Intangible Assets Amortization Expense	Total amortization expenses related to the intangible assets are as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Intangible Asset 2018 2017 2018 2017 Ground leases $ 188 $ 257 $ 633 $ 771 In-place leases 3,320 3,478 10,305 10,322 Franchise agreements and other intangible assets 717 19 755 277 Total $ 4,225 $ 3,754 $ 11,693 $ 11,370
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	We anticipate amortization expense for our intangible assets to be as follows for the next five years (in thousands): Year Remainder of 2018 2019 2020 2021 2022 Estimated expense $ 4,055 $ 15,960 $ 14,232 $ 13,840 $ 9,239

Consolidated Variable Interes_2

Consolidated Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2018
DisclosureofVariableInterestEntities [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the assets and liabilities included in our Consolidated Balance Sheets after eliminations (in thousands): September 30, 2018 December 31, 2017 ASSETS Investment property, net $ 300,693 $ 50,193 Other assets, net 20,655 1,659 TOTAL ASSETS $ 321,348 $ 51,852 LIABILITIES AND STOCKHOLDERS’ EQUITY Debt $ 44,426 $ 41,970 Preferred Equity - Sun NG Resorts - mandatorily redeemable 35,277 — Other liabilities 7,434 1,468 TOTAL LIABILITIES 87,137 43,438 Equity Interests - NG Sun LLC 21,976 — Noncontrolling interests 7,544 4,285 TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY $ 116,657 $ 47,723

Debt And Lines Of Credit (Table

Debt And Lines Of Credit (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of debt and lines of credit [Table Text Block]	The following table sets forth certain information regarding debt including premiums, discounts and deferred financing costs (in thousands): Carrying Amount Weighted Average Years to Maturity Weighted Average Interest Rates September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Collateralized term loans - Life Companies $ 1,253,935 $ 1,044,246 14.4 13.9 4.0 % 3.9 % Collateralized term loans - FNMA 775,383 1,026,014 5.4 5.6 4.4 % 4.4 % Collateralized term loans - CMBS 407,778 410,747 4.3 5.0 5.1 % 5.1 % Collateralized term loans - FMCC 382,129 386,349 6.1 6.9 3.9 % 3.9 % Secured borrowings 113,089 129,182 14.6 15.3 10.0 % 10.0 % Lines of credit — 41,257 0.0 3.1 — % 2.8 % Preferred Equity - Sun NG Resorts - mandatorily redeemable 35,277 — 4.0 - 6.0 % — % Preferred OP units - mandatorily redeemable 37,338 41,443 4.9 5.0 6.6 % 6.7 % Total debt $ 3,004,929 $ 3,079,238 9.4 8.9 4.5 % 4.5 %

Equity and Mezzanine Securiti_2

Equity and Mezzanine Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Sale of Common Stock	Issuances of common stock under the Sales Agreement during 2018 were as follows: Year to Date Common Stock Issued Weighted Average Sales Price Net Proceeds (in Millions) September 30, 2018 1,407,215 $ 95.02 $ 132.0
Activity of Conversions	Nine Months Ended Nine Months Ended Series Conversion Rate Units/Shares Converted Common Stock Units/Shares Converted Common Stock Common OP unit 1 16,908 16,908 25,238 25,238 Series A-1 preferred OP unit 2.439 13,100 31,948 18,319 44,676 Series A-4 preferred OP unit 0.4444 13,765 6,116 9,000 3,996 Series A-4 preferred stock 0.4444 22,576 10,033 158,036 70,238 Series C preferred OP unit 1.11 1,919 2,130 16,806 18,651
Schedule of Dividends Payable	Cash Distributions Record Date Payment Date Distribution per Share Total Distribution (thousands) Common Stock, Common OP units and Restricted Stock 9/28/2018 10/15/2018 $ 0.71 $ 63,250 Series A-4 Preferred Stock 9/14/2018 10/1/2018 $ 0.40625 $ 432

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Share-based Compensation [Abstract]
Schedule of Restricted Stock Granted	The following table shows details on grants of equity awards during the nine months ended September 30, 2018 : Grant Period Type Plan Shares Granted Grant Date Fair Value Per Share Vesting Type Vesting Anniversary Percentage 2018 Key Employees 2015 Equity Incentive Plan 16,500 $ 88.30 (1) Time Based 2nd 35.0 % 3rd 35.0 % 4th 20.0 % 5th 5.0 % 6th 5.0 % 2018 Key Employees 2015 Equity Incentive Plan 47,600 $ 86.22 (1) Time Based 20.0% annually over 5 years 2018 Executive Officers 2015 Equity Incentive Plan 60,000 $ 87.24 (2) Time Based 20.0% annually over 5 years 2018 Executive Officers 2015 Equity Incentive Plan 90,000 $ 65.24 (3) Market Condition 3rd 100.0 % 2018 Directors 2004 Non-Employee Director Option Plan 16,800 $ 85.28 (2) Time Based 3rd 100.0 % (1) The fair value of the grants were determined by using the average closing price of our common stock on the dates the shares were issued. (2) The fair value of the grants were determined by using the closing price of our common stock on the dates the shares were issued. (3) Share-based compensation for restricted stock awards with market conditions is measured based on an estimate of shares expected to vest. We estimate the fair value of share-based compensation for restricted stock with market conditions using a Monte Carlo simulation. At the grant date ,our common stock price was $87.24 . Based on the Monte Carlo simulation we expect 74.8% of the 90,000 shares to vest.

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	A presentation of segment financial information is summarized as follows (in thousands): Three Months Ended September 30, 2018 Three Months Ended September 30, 2017 Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated Revenues $ 257,215 $ 59,720 $ 316,935 $ 215,280 $ 45,954 $ 261,234 Operating expenses/Cost of sales 101,258 39,831 141,089 82,388 31,869 114,257 Net operating income/Gross profit 155,957 19,889 175,846 132,892 14,085 146,977 Adjustments to arrive at net income / (loss): Interest and other revenues, net 6,603 — 6,603 7,011 — 7,011 Home selling expenses — (4,043 ) (4,043 ) — (3,290 ) (3,290 ) General and administrative (17,187 ) (2,940 ) (20,127 ) (15,677 ) (2,497 ) (18,174 ) Transaction costs (24 ) — (24 ) (2,153 ) (14 ) (2,167 ) Depreciation and amortization (54,305 ) (17,677 ) (71,982 ) (48,624 ) (15,608 ) (64,232 ) Loss on extinguishment of debt (939 ) — (939 ) — — — Interest (33,516 ) (5 ) (33,521 ) (32,082 ) (3 ) (32,085 ) Interest on mandatorily redeemable preferred OP units / equity (1,142 ) — (1,142 ) (790 ) — (790 ) Catastrophic weather related charges, net (173 ) — (173 ) (7,718 ) (38 ) (7,756 ) Other income, net 1,230 1 1,231 3,345 — 3,345 Current tax (expense) / benefit (135 ) (78 ) (213 ) 210 (172 ) 38 Deferred tax benefit 199 — 199 81 — 81 Net income / (loss) 56,568 (4,853 ) 51,715 36,495 (7,537 ) 28,958 Less: Preferred return to preferred OP units 1,152 — 1,152 1,112 — 1,112 Less: Amounts attributable to noncontrolling interests 4,304 (233 ) 4,071 2,169 (393 ) 1,776 Net income / (loss) attributable to Sun Communities, Inc. 51,112 (4,620 ) 46,492 33,214 (7,144 ) 26,070 Less: Preferred stock distributions 432 — 432 1,955 — 1,955 Net income / (loss) attributable to Sun Communities, Inc. common stockholders $ 50,680 $ (4,620 ) $ 46,060 $ 31,259 $ (7,144 ) $ 24,115 Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated Revenues $ 671,695 $ 162,205 $ 833,900 592,864 129,093 $ 721,957 Operating expenses/Cost of sales 253,009 107,772 360,781 221,178 84,820 305,998 Net operating income/Gross profit 418,686 54,433 473,119 371,686 44,273 415,959 Adjustments to arrive at net income / (loss): Interest and other revenues, net 18,980 — 18,980 18,587 — 18,587 Home selling expenses — (11,319 ) (11,319 ) — (9,391 ) (9,391 ) General and administrative (52,966 ) (8,466 ) (61,432 ) (49,082 ) (6,830 ) (55,912 ) Transaction costs (138 ) — (138 ) (7,001 ) 11 (6,990 ) Depreciation and amortization (155,624 ) (50,568 ) (206,192 ) (144,143 ) (45,576 ) (189,719 ) Loss on extinguishment of debt (2,657 ) — (2,657 ) (759 ) — (759 ) Interest (96,904 ) (15 ) (96,919 ) (95,754 ) (11 ) (95,765 ) Interest on mandatorily redeemable preferred OP units / equity (2,551 ) — (2,551 ) (2,361 ) — (2,361 ) Catastrophic weather related charges, net 2,206 (219 ) 1,987 (8,075 ) (49 ) (8,124 ) Other (expense) / income, net (3,215 ) 1 (3,214 ) 5,341 (1 ) 5,340 Current tax (expense) / income (366 ) (246 ) (612 ) 145 (278 ) (133 ) Deferred tax benefit 434 — 434 745 — 745 Net income / (loss) 125,885 (16,399 ) 109,486 89,329 (17,852 ) 71,477 Less: Preferred return to preferred OP units 3,335 — 3,335 3,482 — 3,482 Less: Amounts attributable to noncontrolling interests 9,204 (812 ) 8,392 5,148 (969 ) 4,179 Net income / (loss) attributable to Sun Communities, Inc. 113,346 (15,587 ) 97,759 80,699 (16,883 ) 63,816 Less: Preferred stock distributions 1,305 — 1,305 6,233 — 6,233 Net income / (loss) attributable to Sun Communities, Inc. common stockholders $ 112,041 $ (15,587 ) $ 96,454 $ 74,466 $ (16,883 ) $ 57,583
Reconciliation of Assets from Segment to Consolidated	September 30, 2018 December 31, 2017 Real Property Operations Home Sales and Rentals Consolidated Real Property Operations Home Sales and Rentals Consolidated Identifiable assets: Investment property, net $ 5,534,397 $ 519,580 $ 6,053,977 $ 5,172,521 $ 472,833 $ 5,645,354 Cash and cash equivalents 86,857 26,699 113,556 (7,649 ) 17,776 10,127 Inventory of manufactured homes — 41,030 41,030 — 30,430 30,430 Notes and other receivables, net 149,564 18,134 167,698 149,798 13,698 163,496 Collateralized receivables, net 112,228 — 112,228 128,246 — 128,246 Other assets, net 138,451 26,786 165,237 130,455 3,849 134,304 Total assets $ 6,021,497 $ 632,229 $ 6,653,726 $ 5,573,371 $ 538,586 $ 6,111,957

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block]	Computations of basic and diluted earnings per share were as follows (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, Numerator 2018 2017 2018 2017 Net income attributable to common stockholders $ 46,060 $ 24,115 $ 96,454 $ 57,583 Allocation to restricted stock awards (396 ) (189 ) (830 ) (461 ) Basic earnings: Net income attributable to common stockholders after allocation 45,664 23,926 95,624 57,122 Allocation to restricted stock awards 396 189 — 461 Diluted earnings: Net income attributable to common stockholders after allocation $ 46,060 $ 24,115 $ 95,624 $ 57,583 Denominator Weighted average common shares outstanding 81,599 78,369 80,022 75,234 Add: dilutive stock options 2 2 2 2 Add: dilutive restricted stock 480 437 — 610 Diluted weighted average common shares and securities 82,081 78,808 80,024 75,846 Earnings per share available to common stockholders after allocation: Basic $ 0.56 $ 0.31 $ 1.19 $ 0.76 Diluted $ 0.56 $ 0.31 $ 1.19 $ 0.76
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	The following table presents the outstanding securities that were excluded from the computation of diluted earnings per share as of September 30, 2018 and 2017 (in thousands): As of September 30, 2018 2017 Common OP units 2,729 2,757 Series A-1 preferred OP units 332 349 Series A-3 preferred OP units 40 40 Series A-4 preferred OP units 410 425 Series A-4 preferred stock 1,063 1,085 Series C preferred OP units 314 316 Aspen preferred OP units 1,284 1,284 Total securities 6,172 6,256

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	The table below sets forth our financial assets and liabilities that required disclosure of fair value on a recurring basis as of September 30, 2018 . The table presents the carrying values and fair values of our financial instruments as of September 30, 2018 and December 31, 2017 , that were measured using the valuation techniques described above (in thousands). The table excludes other financial instruments such as cash and cash equivalents, accounts receivable, and accounts payable as the carrying values associated with these instruments approximate fair value since their maturities are less than one year. September 30, 2018 December 31, 2017 Financial assets Carrying Value Fair Value Carrying Value Fair Value Installment notes receivable on manufactured homes, net $ 117,583 $ 117,583 $ 115,797 $ 115,797 Collateralized receivables, net $ 112,228 $ 112,228 $ 128,246 $ 128,246 Financial liabilities Debt (excluding secured borrowings) $ 2,891,840 $ 2,798,537 $ 2,908,799 $ 2,726,770 Secured borrowings $ 113,089 $ 113,089 $ 129,182 $ 129,182 Lines of credit $ — $ — $ 41,257 $ 41,257 Other liabilities (contingent consideration) $ 7,261 $ 7,261 $ 6,976 $ 6,976

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	The following table reconciles our beginning-of-period and end-of-period balances of cash, cash equivalents and restricted cash for the periods shown (in thousands): September 30, 2018 December 31, 2017 September 30, 2017 December 31, 2016 Cash and cash equivalents $ 113,556 $ 10,127 $ 137,448 $ 8,164 Restricted cash 15,538 13,382 19,943 17,149 Cash, cash equivalents and restricted cash $ 129,094 $ 23,509 $ 157,391 $ 25,313
Schedule of Cash, Cash Equivalents and Restricted Cash	The following table reconciles our beginning-of-period and end-of-period balances of cash, cash equivalents and restricted cash for the periods shown (in thousands): September 30, 2018 December 31, 2017 September 30, 2017 December 31, 2016 Cash and cash equivalents $ 113,556 $ 10,127 $ 137,448 $ 8,164 Restricted cash 15,538 13,382 19,943 17,149 Cash, cash equivalents and restricted cash $ 129,094 $ 23,509 $ 157,391 $ 25,313

Commitments And Contingencies (

Commitments And Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Business Insurance Recoveries	Nine Months Ended September 30, 2018 Total estimated insurance receivable - December 31, 2017 $ 23.7 Change in estimated insurance recoveries 8.9 Advances from insurer (16.4 ) Total estimated insurance receivable - September 30, 2018 $ 16.2

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 323,538	$ 268,245	$ 852,880	$ 740,544
Income From Real Property [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	229,607	198,263	625,488	560,778
Revenue From Home Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	46,131	33,197	122,248	91,319
Rental Home Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	13,589	12,757	39,957	37,774
Ancillary Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	27,608	17,017	46,207	32,086
Interest [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	5,256	5,920	15,849	15,609
Brokerage Commissions And Other Revenues, Net [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,347	1,091	3,131	2,978
Real Property Operations Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	263,818	222,291	690,675	611,451
Real Property Operations Segment [Member] | Income From Real Property [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	229,607	198,263	625,488	560,778
Real Property Operations Segment [Member] | Revenue From Home Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Real Property Operations Segment [Member] | Rental Home Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Real Property Operations Segment [Member] | Ancillary Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	27,608	17,017	46,207	32,086
Real Property Operations Segment [Member] | Interest [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	5,256	5,920	15,849	15,609
Real Property Operations Segment [Member] | Brokerage Commissions And Other Revenues, Net [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,347	1,091	3,131	2,978
Home Sales and Home Rentals Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	59,720	45,954	162,205	129,093
Home Sales and Home Rentals Segment [Member] | Income From Real Property [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Home Sales and Home Rentals Segment [Member] | Revenue From Home Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	46,131	33,197	122,248	91,319
Home Sales and Home Rentals Segment [Member] | Rental Home Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	13,589	12,757	39,957	37,774
Home Sales and Home Rentals Segment [Member] | Ancillary Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Home Sales and Home Rentals Segment [Member] | Interest [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0	0
Home Sales and Home Rentals Segment [Member] | Brokerage Commissions And Other Revenues, Net [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 0	$ 0	$ 0	$ 0

Revenue Contract Balances (Deta

Revenue Contract Balances (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset, Reclassified to Receivable	$ 19.8	$ 13.8

Real Estate Acquisitions, Sched

Real Estate Acquisitions, Schedule of Properties Acquired (Details)	Sep. 30, 2018sitedevelopment_site	Dec. 31, 2017sitedevelopment_site
Business Acquisition [Line Items]
Sites | site	4,506	2,667
Development Sites | development_site	1,166	18
Archview [Member]
Business Acquisition [Line Items]
Sites | site	114
Development Sites | development_site	50
Petoskey RV Resort [Member]
Business Acquisition [Line Items]
Sites | site	210
Development Sites | development_site	0
The Sands [Member]
Business Acquisition [Line Items]
Sites | site	507
Development Sites | development_site	0
Sun NG RV Resorts [Member]
Business Acquisition [Line Items]
Sites | site	2,700
Development Sites | development_site	940
Silver Creek [Member]
Business Acquisition [Line Items]
Sites | site	264
Development Sites | development_site	176
Highway West [Member]
Business Acquisition [Line Items]
Sites | site	536
Development Sites | development_site	0
Compass [Member]
Business Acquisition [Line Items]
Sites | site	175
Development Sites | development_site	0
Colony In The Wood [Member]
Business Acquisition [Line Items]
Sites | site		383
Development Sites | development_site		0
Emerald Coast [Member]
Business Acquisition [Line Items]
Sites | site		201
Development Sites | development_site		14
Lazy J Ranch [Member]
Business Acquisition [Line Items]
Sites | site		220
Development Sites | development_site		0
Ocean West [Member]
Business Acquisition [Line Items]
Sites | site		130
Development Sites | development_site		4
Caliente Sands [Member]
Business Acquisition [Line Items]
Sites | site		118
Development Sites | development_site		0
Pismo Dunes [Member]
Business Acquisition [Line Items]
Sites | site		331
Development Sites | development_site		0
Arbor Woods [Member]
Business Acquisition [Line Items]
Sites | site		458
Development Sites | development_site		0
Sunset Lakes [Member]
Business Acquisition [Line Items]
Sites | site		498
Development Sites | development_site		0
Far Horizons 49er Village [Member]
Business Acquisition [Line Items]
Sites | site		328
Development Sites | development_site		0

Real Estate Acquisitions, Sch_2

Real Estate Acquisitions, Schedule of Other Acquisitions Purchase Price Allocation (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
At acquistion date
Investment in property			$ 335,669	$ 140,959
Notes receivable				23
Inventory of manufactured homes				488
In-place leases and other intangible assets			16,869	3,260
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			(11,990)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			(3,120)
Total identifiable assets acquired and liabilities assumed			337,428	144,730
Consideration
Cash			280,175	116,218
Equity				28,410
Business Combination, Consideration Transferred, Other Liabilities Incurred, Net			35,277
Liabilities assumed				5,102
Cash proceeds from seller				(5,000)
Total consideration transferred		$ 2,000	337,428	144,730
Lazy J Ranch [Member]
At acquistion date
Investment in property				13,938
Notes receivable				0
Inventory of manufactured homes				2
In-place leases and other intangible assets				360
Total identifiable assets acquired and liabilities assumed				14,300
Consideration
Cash				14,300
Equity				0
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				14,300
Ocean West [Member]
At acquistion date
Investment in property				9,453
Notes receivable				0
Inventory of manufactured homes				0
In-place leases and other intangible assets				220
Total identifiable assets acquired and liabilities assumed				9,673
Consideration
Cash				5,081
Equity				0
Liabilities assumed				4,592
Cash proceeds from seller				0
Total consideration transferred				9,673
Arbor Woods [Member]
At acquistion date
Investment in property				15,725
Notes receivable				23
Inventory of manufactured homes				465
In-place leases and other intangible assets				730
Total identifiable assets acquired and liabilities assumed				16,943
Consideration
Cash				14,943
Equity				2,000
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				16,943
Caliente Sands [Member]
At acquistion date
Investment in property				8,640
Notes receivable				0
Inventory of manufactured homes				21
In-place leases and other intangible assets				210
Total identifiable assets acquired and liabilities assumed				8,871
Consideration
Cash				8,871
Equity				0
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				8,871
Pismo Dunes [Member]
At acquistion date
Investment in property				21,260
Notes receivable				0
Inventory of manufactured homes				0
In-place leases and other intangible assets				660
Total identifiable assets acquired and liabilities assumed				21,920
Consideration
Cash				0
Equity				26,410
Liabilities assumed				510
Cash proceeds from seller				(5,000)
Total consideration transferred	$ 26,400			21,920
Colony In The Wood [Member]
At acquistion date
Investment in property				31,818
Notes receivable				0
Inventory of manufactured homes				0
In-place leases and other intangible assets				660
Total identifiable assets acquired and liabilities assumed				32,478
Consideration
Cash				32,478
Equity				0
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				32,478
Emerald Coast [Member]
At acquistion date
Investment in property				19,400
Notes receivable				0
Inventory of manufactured homes				0
In-place leases and other intangible assets				100
Total identifiable assets acquired and liabilities assumed				19,500
Consideration
Cash				19,500
Equity				0
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				19,500
Silver Creek [Member]
At acquistion date
Investment in property			7,250
In-place leases and other intangible assets			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			0
Total identifiable assets acquired and liabilities assumed			7,250
Consideration
Cash			7,250
Equity			0
Total consideration transferred			7,250
Highway West [Member]
At acquistion date
Investment in property			36,500
In-place leases and other intangible assets			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			0
Total identifiable assets acquired and liabilities assumed			36,500
Consideration
Cash			36,500
Equity			0
Total consideration transferred			36,500
Compass [Member]
At acquistion date
Investment in property			13,930
In-place leases and other intangible assets			70
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			0
Total identifiable assets acquired and liabilities assumed			14,000
Consideration
Cash			14,000
Equity			0
Total consideration transferred			14,000
Archview [Member]
At acquistion date
Investment in property			14,550
In-place leases and other intangible assets			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			0
Total identifiable assets acquired and liabilities assumed			14,550
Consideration
Cash			14,550
Equity			0
Total consideration transferred			14,550
Petoskey RV Resort [Member]
At acquistion date
Investment in property			9,000
In-place leases and other intangible assets			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			0
Total identifiable assets acquired and liabilities assumed			9,000
Consideration
Cash			9,000
Equity			0
Total consideration transferred			9,000
The Sands [Member]
At acquistion date
Investment in property			13,790
In-place leases and other intangible assets			460
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			0
Total identifiable assets acquired and liabilities assumed			14,250
Consideration
Cash			14,250
Equity			0
Total consideration transferred			14,250
Sun NG RV Resorts [Member]
At acquistion date
Investment in property			240,649
In-place leases and other intangible assets			16,339
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities			(11,990)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			(3,120)
Total identifiable assets acquired and liabilities assumed			241,878
Consideration
Cash			184,625
Business Combination, Consideration Transferred, Other Liabilities Incurred, Net			35,277
Total consideration transferred			241,878
Far Horizons 49er Village [Member]
At acquistion date
Investment in property				12,890
Notes receivable				0
Inventory of manufactured homes				0
In-place leases and other intangible assets				110
Total identifiable assets acquired and liabilities assumed				13,000
Consideration
Cash				13,000
Equity				0
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				13,000
Sunset Lakes [Member]
At acquistion date
Investment in property				7,835
Notes receivable				0
Inventory of manufactured homes				0
In-place leases and other intangible assets				210
Total identifiable assets acquired and liabilities assumed				8,045
Consideration
Cash				8,045
Equity				0
Liabilities assumed				0
Cash proceeds from seller				0
Total consideration transferred				$ 8,045
Series A Preferred Stock [Member]
Consideration
Equity			21,976
Series A Preferred Stock [Member] | Silver Creek [Member]
Consideration
Equity			0
Series A Preferred Stock [Member] | Highway West [Member]
Consideration
Equity			0
Series A Preferred Stock [Member] | Compass [Member]
Consideration
Equity			0
Series A Preferred Stock [Member] | Archview [Member]
Consideration
Equity			0
Series A Preferred Stock [Member] | Petoskey RV Resort [Member]
Consideration
Equity			0
Series A Preferred Stock [Member] | The Sands [Member]
Consideration
Equity			0
Series A Preferred Stock [Member] | Sun NG RV Resorts [Member]
Consideration
Equity			$ 21,976

Real Estate Acquisitions, Sch_3

Real Estate Acquisitions, Schedule of Land Acquired (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)development_site	Dec. 31, 2017USD ($)development_site
Business Acquisition [Line Items]
Development Sites | development_site		1,612	841
Cost | $	$ 8	$ 7.5
Carolina Pines [Member]
Business Acquisition [Line Items]
Development Sites | development_site			841
Cost | $			$ 5.9
Pecan Park [Member]
Business Acquisition [Line Items]
Development Sites | development_site		158
Cost | $		$ 1.3
Smith Creek Crossing [Member]
Business Acquisition [Line Items]
Development Sites | development_site		310
Cost | $		$ 0.9
River Run Ranch [Member]
Business Acquisition [Line Items]
Development Sites | development_site		1,144
Cost | $		$ 5.3

Real Estate Acquisitions, Pro F

Real Estate Acquisitions, Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Total revenues	$ 26,317		$ 33,433
Net income attributable to Sun Communities, Inc. common stockholders	7,529		11,356
Acquisitions - 2018 [Member]
Business Acquisition [Line Items]
Total revenues	325,504	$ 296,322	861,193	$ 780,529
Net income attributable to Sun Communities, Inc. common stockholders	$ 57,413	$ 42,987	$ 93,714	$ 68,378
Net income per share attributable to Sun Communities, Inc. common stockholders - basic	$ 0.70	$ 0.55	$ 1.17	$ 0.91
Net income per share attributable to Sun Communities, Inc. common stockholders - diluted	$ 0.70	$ 0.55	$ 1.17	$ 0.90

Collateralized Receivables an_3

Collateralized Receivables and Transfers of Financial Assets, Repurchase price percentage (Details) - Collateralized Receivables [Member]	9 Months Ended
	Sep. 30, 2018
Less than or equal to 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repurchase Percentage	100.00%
Greater than 15 but less than 64 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repurchase Percentage	90.00%
Equal to or greater than 64 but less than 120 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repurchase Percentage	65.00%
120 or more [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repurchase Percentage	50.00%

Collateralized Receivables an_4

Collateralized Receivables and Transfers of Financial Assets, Schedule of collateralized loans (Details) - Collateralized Receivables [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal payments and payoffs from our customers	$ (9,386)
Principal reduction from repurchased homes	6,707
Total activity	(16,093)
Ending balance	113,089
Secured Debt [Member] | Fair Value, Measurements, Recurring [Member] | Reported Value Measurement [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	129,182
Ending balance	$ 113,089

Collateralized Receivables an_5

Collateralized Receivables and Transfers of Financial Assets Collateralized Receivables and Transfers of Financial Assets, Allowance for Collateralized Receivables (Details) - Collateralized Receivables [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 936
Lower of cost or market write-downs	587
Increase to reserve balance	512
Total activity	75
Ending balance	$ (861)

Collateralized Receivables an_6

Collateralized Receivables and Transfers of Financial Assets, Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes and other receivables, net	$ 167,698		$ 167,698		$ 163,496
Interest income and expense, net	2,800	$ 3,300		$ 9,900
Collateralized Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Allowance	(861)		$ (861)		$ 936
Receivable With Imputed Interest, Term			14 years 3 months 22 days		15 years 3 months 18 days
Financing Receivable, Gross	113,089		$ 113,089
Receivable with Imputed Interest, Effective Yield (Interest Rate)			10.00%		10.00%
Reported Value Measurement [Member] | Collateralized Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes and other receivables, net	112,200		$ 112,200		$ 128,246
Secured Debt [Member] | Fair Value, Measurements, Recurring [Member] | Reported Value Measurement [Member] | Collateralized Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 113,089		$ 113,089		$ 129,182

Notes and Other Receivables, Sc

Notes and Other Receivables, Schedule of notes and other receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes and other receivables, net	$ 167,698	$ 163,496
Other receivables, net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes and other receivables, net	$ 50,115	47,699
Reported Value Measurement [Member] | Installment notes receivable on manufactured homes, net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes and other receivables, net		$ 115,797

Notes And Other Receivables Not

Notes And Other Receivables Notes and Other Receivables, Installment notes receivable on manufactured homes - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and Notes Receivable, Net	$ 167,698	$ 163,496
Installment notes receivable on manufactured homes, net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Allowance	$ (600)	$ (400)
Receivable with Imputed Interest, Effective Yield (Interest Rate)	8.00%	8.20%
Receivable With Imputed Interest, Term	16 years 10 months 6 days	17 years 2 months 12 days
Reported Value Measurement [Member] | Installment notes receivable on manufactured homes, net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and Notes Receivable, Net		$ 115,797
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Installment notes receivable on manufactured homes, net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and Notes Receivable, Net	$ 117,583

Notes and Other Receivables, _2

Notes and Other Receivables, Schedule of installment notes receivable (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Collateralized receivables, net and Installment Notes Receivables on Manufactured Homes [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase to reserve balance	$ 761
Installment notes receivable on manufactured homes, gross [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	116,174
Financed sales of manufactured homes	14,042
Principal payments and payoffs from our customers	(6,721)
Principal reduction from repossessed homes	5,296
Total activity	2,025
Ending balance	$ 118,199

Notes and Other Receivables, Al

Notes and Other Receivables, Allowance for installment notes receivable (Details) - Collateralized receivables, net and Installment Notes Receivables on Manufactured Homes [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 377
Lower of cost or market write-downs	522
Increase to reserve balance	761
Total activity	(239)
Ending balance	$ (616)

Notes And Other Receivables N_2

Notes And Other Receivables Notes and Other Receivables, Other receivables - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other receivables for rent, water, sewer usage	$ 7.9	$ 7
Allowance for rent, water, sewer usage receivables	(1.8)	(1.5)
Contract with Customer, Asset, Reclassified to Receivable	19.8	13.8
Insurance receivables	$ 22.4	$ 26.9

Intangible Assets Intangible _2

Intangible Assets Intangible Assets, Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 151,179	$ 134,888
Accumulated Amortization	(59,826)	(48,436)
Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	31,060	32,165
Accumulated Amortization	$ (1,755)	(1,409)
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Gross Carrying Amount	$ 103,598	100,843
Accumulated Amortization	(55,881)	(45,576)
Franchise Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	16,521	1,880
Accumulated Amortization	$ (2,190)	$ (1,451)
Minimum [Member] | Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years
Minimum [Member] | Franchise Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Maximum [Member] | Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	57 years
Maximum [Member] | Franchise Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years

Intangible Assets Intangible _3

Intangible Assets Intangible Assets, Schedule of Intangible Asset Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 4,225	$ 3,754	$ 11,693	$ 11,370
Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	188	257	633	771
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	3,320	3,478	10,305	10,322
Franchise Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 717	$ 19	$ 755	$ 277

Intangible Assets, Intangibles

Intangible Assets, Intangibles Future Amortization Expense (Details) $ in Thousands	Sep. 30, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2018	$ 4,055
2,018	15,960
2,019	14,232
2,020	13,840
2,021	$ 9,239

Intangible Assets Intangible _4

Intangible Assets Intangible Assets, Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2018	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Ground Leases, Percent Of Land Acquired	50.00%
Payments to Acquire Land	$ 8	$ 7.5
Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0
Finite-Lived Intangible Assets, Accumulated Amortization	0
Finite-Lived Intangible Assets, Net	$ 0

Investment In Affiliates , Narr

Investment In Affiliates , Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Schedule of Equity Method Investments [Line Items]
Net income from investment	$ 0.1
GTSC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	40.00%
Investment carrying value	$ 19.9

Consolidated Variable Interes_3

Consolidated Variable Interest Entities, Schedule of Variable Interest Entities (Details)	1 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)sitesitespropertiesRate	Dec. 31, 2017USD ($)siteRate
Variable Interest Entity [Line Items]
Investment property, net		$ 6,053,977,000	$ 5,645,354,000
Other assets, net (including $20,655 and $1,659 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		165,237,000	134,304,000
Mortgage loans payable (including $44,426 and $41,970 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		2,819,225,000	2,867,356,000
Other liabilities (including $7,434 and $1,468 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		163,459,000	138,536,000
Liabilities		3,367,285,000	3,405,204,000
Consolidated variable interest entities		$ 7,544,000	$ 4,285,000
VIE as a Percentage of Consolidated Assets | Rate		4.80%	0.80%
VIE as a Percentage of Consolidated Liabilities | Rate		2.60%	1.20%
VIE as a Percentage of Total Equity		1.00%
Sites | site		4,506	2,667
Cash		$ 280,175,000	$ 116,218,000
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investment property, net		300,693,000	50,193,000
Other assets, net (including $20,655 and $1,659 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		20,655,000	1,659,000
Total Assets		321,348,000	51,852,000
Mortgage loans payable (including $44,426 and $41,970 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		44,426,000	41,970,000
Preferred OP units - mandatorily redeemable		35,277,000	0
Other liabilities (including $7,434 and $1,468 for consolidated variable interest entities at September 30, 2018 and December 31, 2017; see Note 8)		7,434,000	1,468,000
Liabilities		87,137,000	43,438,000
Equity Interests		21,976,000	0
Consolidated variable interest entities		7,544,000	4,285,000
Total Liabilities and Stockholder's Equity		116,657,000	47,723,000
Preferred Equity, Mandatorily Redeemable [Member]
Variable Interest Entity [Line Items]
Preferred OP units - mandatorily redeemable		35,277,000	$ 0
Northgate Additional Consideration [Member]
Variable Interest Entity [Line Items]
Cash		$ 0
Northgate [Member]
Variable Interest Entity [Line Items]
Number of Real Estate Properties | properties		10
Sites | sites		2,700
Northgate [Member] | Sun NG RV Resorts [Member]
Variable Interest Entity [Line Items]
Ownership percentage		80.00%
Payments to Acquire Interest in Joint Venture	$ 61.6
Northgate [Member] | NG Sun LLC [Member]
Variable Interest Entity [Line Items]
Ownership percentage		20.00%
Payments to Acquire Interest in Joint Venture	$ 15.4
Development Sites [Member] | Northgate [Member]
Variable Interest Entity [Line Items]
Sites | sites		940
Ground Up Development [Member] | Northgate [Member]
Variable Interest Entity [Line Items]
Number of Real Estate Properties | properties		1
Preferred Partner [Member] | Northgate Additional Consideration [Member]
Variable Interest Entity [Line Items]
Cash		$ 0
Bridge Loan [Member] | Northgate Additional Consideration [Member]
Variable Interest Entity [Line Items]
Cash		$ 0

Debt And Lines Of Credit , Sche

Debt And Lines Of Credit , Schedule of debt and lines of credit (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Secured debt	$ 2,867,356		$ 2,819,225	$ 2,819,225	$ 2,867,356
Debt weighted average to maturity, years				9 years 4 months 28 days	8 years 10 months 24 days
Weighted average interest rate	4.50%		4.50%	4.50%	4.50%
Lines of credit	$ 41,257				$ 41,257
Total debt	3,079,238		$ 3,004,929	$ 3,004,929	3,079,238
Collateralized term loans - CMBS [Member]
Debt Instrument [Line Items]
Secured debt	$ 410,747		$ 775,383	$ 775,383	$ 410,747
Debt weighted average to maturity, years				5 years 4 months 21 days	5 years
Weighted average interest rate	5.10%		4.40%	4.40%	5.10%
Secured borrowing [Member]
Debt Instrument [Line Items]
Debt instrument term	30 years	25 years	20 years
Preferred OP units [Member]
Debt Instrument [Line Items]
Secured debt			$ 37,338	$ 37,338
Preferred OP units - mandatorily redeemable	$ 41,443		$ 37,338	$ 37,338	$ 41,443
Debt weighted average to maturity, years				14 years 6 months 26 days	5 years
Weighted average interest rate	6.70%		10.00%	10.00%	6.70%
Preferred Equity, Mandatorily Redeemable [Member]
Debt Instrument [Line Items]
Preferred OP units - mandatorily redeemable	$ 0		$ 35,277	$ 35,277	$ 0
Debt instrument term				4 years 4 days
Weighted average interest rate	0.00%		6.00%	6.00%	0.00%
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Debt Instrument [Line Items]
Secured debt	$ 1,026,014		$ 382,129	$ 382,129	$ 1,026,014
Debt weighted average to maturity, years				6 years 1 month 17 days	5 years 7 months 6 days
Weighted average interest rate	4.40%		3.90%	3.90%	4.40%
Life Companies [Member] | Collateralized Mortgage Backed Securities [Member]
Debt Instrument [Line Items]
Secured debt	$ 1,044,246		$ 1,253,935	$ 1,253,935	$ 1,044,246
Debt weighted average to maturity, years				14 years 4 months 21 days	13 years 10 months 24 days
Weighted average interest rate	3.90%		4.00%	4.00%	3.90%
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Debt Instrument [Line Items]
Secured debt	$ 386,349		$ 407,778	$ 407,778	$ 386,349
Debt weighted average to maturity, years				4 years 3 months 7 days	6 years 10 months 24 days
Weighted average interest rate	3.90%		5.10%	5.10%	3.90%
Reported Value Measurement [Member] | Secured borrowing [Member]
Debt Instrument [Line Items]
Secured debt	$ 129,182		$ 113,089	$ 113,089	$ 129,182
Secured borrowings on collateralized receivables	$ 129,182				$ 129,182
Debt weighted average to maturity, years				4 years 10 months 21 days	15 years 3 months 18 days
Weighted average interest rate	10.00%		6.60%	6.60%	10.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Lines of credit			$ 0	$ 0
Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Debt weighted average to maturity, years				0 years	3 years 1 month 6 days
Weighted average interest rate	2.80%		0.00%	0.00%	2.80%

Debt And Lines Of Credit , Narr

Debt And Lines Of Credit , Narrative - Collateralized Term Loans (Details)	1 Months Ended			3 Months Ended						9 Months Ended		12 Months Ended
	Dec. 31, 2017USD ($)site	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Sep. 30, 2018USD ($)sitesitesproperties	Jun. 30, 2018USD ($)community	Mar. 31, 2018USD ($)community	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)community	Sep. 30, 2018USD ($)sitesitesproperties	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)site
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt				$ 939,000			$ 0	$ 300,000	$ 500,000	$ 2,657,000	$ 759,000
Reduction in secured borrowing balance										$ 16,093,000	17,674,000
Number of Real Estate Units Released | community					11	3			1
Weighted average interest rate	4.50%			4.50%						4.50%		4.50%
Sites | site	2,667			4,506						4,506		2,667
Debt weighted average to maturity, length										9 years 4 months 28 days		8 years 10 months 24 days
Total debt	$ 2,867,356,000			$ 2,819,225,000						$ 2,819,225,000		$ 2,867,356,000
Secured Debt [Member]
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt				300,000	$ 0	$ 200,000
Reduction in secured borrowing balance				30,500,000	$ 0	$ 24,400,000
Debt Instrument, Interest Rate, Stated Percentage	4.25%											4.25%
Debt instrument, face amount	$ 100,000,000		$ 77,000,000	$ 228,000,000				$ 77,000,000		$ 228,000,000		$ 100,000,000
Interest rate	6.34%		4.16%	4.10%	4.53%	6.36%		4.16%		4.10%		6.34%
Debt instrument term	30 years		25 years	20 years
Commercial Mortgage Backed Securities [Member]
Debt Instrument [Line Items]
Weighted average interest rate	5.10%			4.40%						4.40%		5.10%
Debt weighted average to maturity, length										5 years 4 months 21 days		5 years
Total debt	$ 410,747,000			$ 775,383,000						$ 775,383,000		$ 410,747,000
Collateralized Mortgage Backed Securities [Member]
Debt Instrument [Line Items]
Net book value of properties securing collateralized term loans				$ 3,200,000,000						$ 3,200,000,000
Properties securing debt [Member] | Collateralized Mortgage Backed Securities [Member]
Debt Instrument [Line Items]
Sites | sites				72,620						72,620
Debt Instrument, number of properties securing a debt instument | properties				185						185
Collateralized Term Loan Due June 1, 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Defeased	38,600,000
Gain (loss) on extinguishment of debt	$ 5,200,000
Debt Instrument, Interest Rate, Stated Percentage	5.25%											5.25%
Collateralized Term Loan Due August 31, 2017 [Member]
Debt Instrument [Line Items]
Reduction in secured borrowing balance			$ 3,900,000
Debt Instrument, Interest Rate, Stated Percentage			6.54%					6.54%
Collateralized Term Loan Due August 1, 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Defeased									$ 18,900,000
Debt Instrument, Interest Rate, Stated Percentage									6.49%
Collateralized Term Loan Due May 1, 2017 [Member]
Debt Instrument [Line Items]
Reduction in secured borrowing balance									$ 10,000,000
Debt Instrument, Interest Rate, Stated Percentage									5.57%
Ocean West [Member]
Debt Instrument [Line Items]
Sites | site	130											130
Ocean West [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 4,600,000					$ 4,600,000				$ 4,600,000
Interest rate		4.34%					4.34%				4.34%
Debt instrument term		9 years 9 months 18 days

Debt And Lines Of Credit , Na_2

Debt And Lines Of Credit , Narrative - Aspen Preferred OP Units and Series B-3 preferred OP units (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2018
Debt Instrument [Line Items]
Stock Redeemed or Called During Period, Shares		3,400,000
Stock Redeemed or Called During Period, Value		$ 85.5
Financial Instruments Subject to Mandatory Redemption, Rate Of Return	600.00%
Preferred Equity, Mandatorily Redeemable [Member]
Debt Instrument [Line Items]
Financial Instruments Subject to Mandatory Redemption, Value of Shares Issued			$ 35.3
Preferred OP units [Member] | Convertible debt - Aspen Preferred OP Units January 2024 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 34.7
Convertible units to shares (in shares)			447,674
Debt Instrument, Interest Rate During Period			6.50%
Debt Instrument, Convertible, Conversion Price			$ 68
Conversion of Stock, Shares Converted			0.397
Series B-3 Preferred OP Units [Member] | Convertible debt - Aspen Preferred OP Units January 2024 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 6.7	$ 2.7
Debt Instrument, Convertible, Conversion Price			$ 100
Series B-3 Preferred OP Units [Member]
Debt Instrument [Line Items]
Stock Redeemed or Called During Period, Shares			41,051
Redemption price including accrued and unpaid dividends (in dollars per share)			$ 100.065753
Stock Redeemed or Called During Period, Value			$ 4.1

Debt And Lines Of Credit , Na_3

Debt And Lines Of Credit , Narrative - Line of Credit (Details)	1 Months Ended	3 Months Ended			9 Months Ended	12 Months Ended
	Apr. 30, 2017	Jun. 30, 2018community	Mar. 31, 2018community	Mar. 31, 2017community	Sep. 30, 2018USD ($)Rate	Dec. 31, 2017USD ($)	Apr. 25, 2017USD ($)Rate
Line of Credit Facility [Line Items]
Lines of credit						$ 41,257,000
Weighted average interest rate					4.50%	4.50%
Debt weighted average to maturity, length					9 years 4 months 28 days	8 years 10 months 24 days
Number of Real Estate Units Released | community		11	3	1
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity							$ 650,000,000
Line of credit, borrowing capacity							900,000,000
Debt Instrument, Maturity Date	Apr. 25, 2021
Line of credit, additional borrowing capacity							350,000,000
Letters of credit outstanding, amount					$ 4,200,000	$ 1,300,000
Line of credit - manufactured home floor plan facility [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity					12,000,000
Lines of credit					$ 0	$ 4,000,000
Weighted average interest rate | Rate					7.00%
Prime Rate [Member] | Line of credit - manufactured home floor plan facility [Member]
Line of Credit Facility [Line Items]
Basis points | Rate					100.00%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity							550,000,000
Long-term Debt					$ 0
Lines of credit					$ 0
Revolving Credit Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Weighted average interest rate					0.00%	2.80%
Debt weighted average to maturity, length					0 years	3 years 1 month 6 days
Revolving Credit Facility [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit variable interest rate | Rate					1.35%
Term Loan [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity							$ 100,000,000
Long-term Debt					$ 0
Term Loan [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit variable interest rate | Rate					1.30%
Minimum [Member] | Revolving Credit Facility [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Interest rate | Rate							1.35%
Minimum [Member] | Term Loan [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Interest rate | Rate							1.30%
Maximum [Member] | Prime Rate [Member] | Line of credit - manufactured home floor plan facility [Member]
Line of Credit Facility [Line Items]
Interest rate | Rate					6.00%
Maximum [Member] | Revolving Credit Facility [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Interest rate | Rate							2.20%
Maximum [Member] | Term Loan [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Interest rate | Rate							2.15%

Equity and Mezzanine Securiti_3

Equity and Mezzanine Securities, Narrative (Details) - USD ($)	Oct. 15, 2018	Oct. 01, 2018	Sep. 30, 2018	Jun. 30, 2018	Jul. 31, 2017	Jun. 30, 2017	May 31, 2017	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Sep. 30, 2018	Nov. 30, 2017	Nov. 30, 2004
Class of Stock [Line Items]
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount			$ 21,976,000					$ 21,976,000	$ 0		$ 21,976,000		$ 0	$ 21,976,000
Issuance of common stock and common OP units, net								$ 132,000,000			$ 624,152,000			$ 163,800,000
Shares Issued, Weighted Average Price Per Share			$ 95.02					$ 95.02			$ 95.02			$ 95.02
Aggregate Value of Shares to be Issued in Accordance to Sales Agreement											$ 450,000,000
Commission, Maximum Percentage of Gross Sales Price Per Share According to Sales Agreement											2.00%
New shares issued (in shares)			5,060,000				4,830,000	1,407,215
Proceeds from Issuance of Common Stock			$ 499,900,000				$ 408,900,000
Redemption price (in dollars per share)			$ 25					$ 25			$ 25			$ 25	$ 25.14349
Stock Redeemed or Called During Period, Shares									3,400,000
Stock Redeemed or Called During Period, Value									$ 85,500,000
Total consideration transferred										$ 2,000,000	$ 337,428,000		144,730,000
Series A-4 Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared								0.40625
Stock Redeemed or Called During Period, Shares						438,448
Series A-4 Preferred Stock | Subsequent Event
Class of Stock [Line Items]
Payments of dividends		$ 432,000
Common Stock
Class of Stock [Line Items]
Dividends per common share								$ 0.71
Common Stock | Subsequent Event
Class of Stock [Line Items]
Payments of dividends	$ 63,250,000
Common OP Units
Class of Stock [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares						23,311
Series A-4 preferred OP units
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares						200,000
Common Stock
Class of Stock [Line Items]
Issuance of common stock and common OP units, net											$ 66,000
Authorized to be repurchased (in shares)																1,000,000
Remaining number of shares authorized to be repurchased (in shares)			400,000					400,000			400,000			400,000
Conversion of Common OP Units to common stock (in shares)											1,000
Series A-4 preferred OP units
Class of Stock [Line Items]
Conversion of Common OP Units to common stock (in shares)											13,765	9,000
Series A-4 preferred OP units | Common OP Units
Class of Stock [Line Items]
Conversion of Common OP Units to common stock (in shares)											6,116	3,996
Conversion of Common OP Units
Class of Stock [Line Items]
Conversion of Common OP Units to common stock (in shares)											16,908	25,238
Conversion of Common OP Units | Common OP Units
Class of Stock [Line Items]
Conversion of Common OP Units to common stock (in shares)											16,908
Series A-1 Preferred OP Units
Class of Stock [Line Items]
Conversion of Common OP Units to common stock (in shares)											13,100	18,319
Series A-1 Preferred OP Units | Common OP Units
Class of Stock [Line Items]
Conversion of Common OP Units to common stock (in shares)											31,948	44,676
Pismo Dunes [Member]
Class of Stock [Line Items]
Total consideration transferred					$ 26,400,000								$ 21,920,000
Pismo Dunes [Member] | Common OP Units
Class of Stock [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares					298,900
Green Courte [Member] | Series A-4 Preferred Stock and OP Units [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Value						$ 24,700,000
Payments of Dividends						$ 200,000
NG Sun LLC [Member] | Sun NG RV Resorts [Member]
Class of Stock [Line Items]
Variable Interest Entity, Equity Interests Issued				$ 6.5
Variable Interest Entity, Equity Interests Issued, Floating Rate				5.00%
Sun NG RV Resorts [Member] | Common Stock | Sun NG RV Resorts [Member]
Class of Stock [Line Items]
Variable Interest Entity, Equity Interests Issued				$ 15.4

Equity and Mezzanine Securiti_4

Equity and Mezzanine Securities, Conversion of Stock (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Nov. 30, 2017
Conversion of Stock [Line Items]
Redemption price (in dollars per share)		$ 25		$ 25.14349
Stock Redeemed or Called During Period, Value	$ 85.5
Stock Redeemed or Called During Period, Shares	3,400,000
Conversion of Common OP Units
Conversion of Stock [Line Items]
Conversion of units		16,908	25,238
Series A-1 Preferred OP Units
Conversion of Stock [Line Items]
Conversion of units		13,100	18,319
Series A-4 preferred OP units
Conversion of Stock [Line Items]
Conversion of units		13,765	9,000
Series A-4 Preferred Stock
Conversion of Stock [Line Items]
Conversion of units		22,576	158,036
Series C preferred OP unit
Conversion of Stock [Line Items]
Conversion of units		1,919	16,806
Common OP Units | Conversion of Common OP Units
Conversion of Stock [Line Items]
Conversion Rate		1,000
Conversion of units		16,908
Common OP Units | Series A-1 Preferred OP Units
Conversion of Stock [Line Items]
Conversion Rate		2,439
Conversion of units		31,948	44,676
Common OP Units | Series A-4 preferred OP units
Conversion of Stock [Line Items]
Conversion Rate		444.4000
Conversion of units		6,116	3,996
Common OP Units | Series A-4 Preferred Stock
Conversion of Stock [Line Items]
Conversion Rate		444.4000
Conversion of units		10,033	70,238
Common OP Units | Series C preferred OP unit
Conversion of Stock [Line Items]
Conversion Rate		1,110
Conversion of units		2,130	18,651

Equity and Mezzanine Securiti_5

Equity and Mezzanine Securities Equity and Mezzanine Securities, Dividends Payable Table (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 15, 2018	Oct. 01, 2018	Sep. 28, 2018	Sep. 14, 2018	Sep. 30, 2018
Common Stock
Dividends Payable [Line Items]
Dividends Payable, Date of Record			Sep. 28, 2018
Dividends per common share					$ 0.71
Series A-4 Preferred Stock
Dividends Payable [Line Items]
Dividends Payable, Date of Record				Sep. 14, 2018
Preferred Stock, Dividends Per Share, Declared					$ 0.40625
Subsequent Event | Common Stock
Dividends Payable [Line Items]
Dividends Payable, Date to be Paid	Oct. 15, 2018
Payments of dividends	$ 63,250
Subsequent Event | Series A-4 Preferred Stock
Dividends Payable [Line Items]
Dividends Payable, Date to be Paid		Oct. 1, 2018
Payments of dividends		$ 432

Equity and Mezzanine Securiti_6

Equity and Mezzanine Securities Equity and Mezzanine Securities, Schedule of Sale of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended	9 Months Ended	15 Months Ended
	Sep. 30, 2018	May 31, 2017	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2018
Aggregate Value of Shares to be Issued in Accordance to Sales Agreement				$ 450,000
Proceeds from Issuance of Common Stock	$ 499,900	$ 408,900
New shares issued (in shares)	5,060,000	4,830,000	1,407,215
Shares Issued, Weighted Average Price Per Share	$ 95.02		$ 95.02	$ 95.02	$ 95.02
Issuance of common stock and common OP units, net			$ 132,000	$ 624,152	$ 163,800

Share-Based Compensation (Detai

Share-Based Compensation (Details)	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Price | $ / shares	$ 87.24
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Percentage	74.80%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	90,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested restricted stock (in shares)	202,368
Grant One [Member] | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares (in shares)	16,500
Weighted average grant date fair value | $ / shares	$ 88.30
Grant One [Member] | Third Anniversary | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	35.00%
Grant One [Member] | Fourth Anniversary | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	35.00%
Grant One [Member] | Fifth Anniversary | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	20.00%
Grant One [Member] | Sixth Anniversary | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	5.00%
Grant One [Member] | Seventh Anniversary | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	5.00%
Grant Two [Member] | Key Employees [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares (in shares)	47,600
Weighted average grant date fair value | $ / shares	$ 86.22
Grant Three [Member] | Executive Officer [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares (in shares)	60,000
Weighted average grant date fair value | $ / shares	$ 87.24
Grant Four [Member] | Executive Officer [Member] | Restricted Stock [Member] | 2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares (in shares)	90,000
Weighted average grant date fair value | $ / shares	$ 65.24
Award vesting percentage	100.00%
Grant Five [Member] | Director [Member] | Restricted Stock [Member] | 2004 Non-employee Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, shares (in shares)	16,800
Weighted average grant date fair value | $ / shares	$ 85.28
Award vesting percentage	100.00%

Segment Reporting Segment Repor

Segment Reporting Segment Reporting, Seasonality (Details) $ in Millions	3 Months Ended								9 Months Ended
	Dec. 31, 2018	Sep. 30, 2018USD ($)	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017USD ($)	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018USD ($)segment
Segment Reporting Information [Line Items]
Number of reportable segments | segment									2
Real Property Operations Segment [Member]
Segment Reporting Information [Line Items]
Expected annual transient RV revenue | $		$ 107.6			$ 78				$ 107.6
Transient RV rental revenue recognized as a percentage		42.00%	20.10%	20.40%	15.80%	36.90%	20.10%	27.20%
Scenario, Forecast [Member] | Real Property Operations Segment [Member]
Segment Reporting Information [Line Items]
Transient RV rental revenue recognized as a percentage	17.50%

Segment Reporting Results of Op

Segment Reporting Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenues	$ 316,935	$ 261,234			$ 833,900	$ 721,957
Operating expenses/Cost of sales	141,089	114,257			360,781	305,998
Net operating income/Gross profit	175,846	146,977			473,119	415,959
Interest and other revenues, net	6,603	7,011			18,980	18,587
Home selling expenses	(4,043)	(3,290)			(11,319)	(9,391)
General and administrative	(20,127)	(18,174)			(61,432)	(55,912)
Transaction costs	(24)	(2,167)			(138)	(6,990)
Depreciation and amortization	(71,982)	(64,232)			(206,192)	(189,719)
Loss on extinguishment of debt	(939)	0	$ (300)	$ (500)	(2,657)	(759)
Interest	(33,521)	(32,085)			(96,919)	(95,765)
Interest on mandatorily redeemable preferred OP units / equity	(1,142)	(790)			(2,551)	(2,361)
Catastrophic weather related charges	173	7,756			1,987	8,124
Other income / (expense), net	1,231	3,345			(3,214)	5,340
Current tax (expense) / benefit	(213)	38			(612)	(133)
Deferred tax benefit	(199)	(81)			(434)	(745)
Net income	51,715	28,958			109,486	71,477
Less: Preferred return to Series A-1 preferred OP units	1,152	1,112			3,335	3,482
Less: Amounts attributable to noncontrolling interests	4,071	1,776			8,392	4,179
Net income attributable to Sun Communities, Inc.	46,492	26,070			97,759	63,816
Less: Preferred stock distributions	432	1,955			1,305	6,233
Net income attributable to Sun Communities, Inc. common stockholders	46,060	24,115			96,454	57,583
Real Property Operations Segment [Member]
Segment Reporting Information [Line Items]
Revenues	257,215	215,280			671,695	592,864
Operating expenses/Cost of sales	101,258	82,388			253,009	221,178
Net operating income/Gross profit	155,957	132,892			418,686	371,686
Interest and other revenues, net	6,603	7,011			18,980	18,587
Home selling expenses	0	0			0	0
General and administrative	(17,187)	(15,677)			(52,966)	(49,082)
Transaction costs	(24)	(2,153)			(138)	(7,001)
Depreciation and amortization	(54,305)	(48,624)			(155,624)	(144,143)
Loss on extinguishment of debt	(939)	0			(2,657)	(759)
Interest	(33,516)	(32,082)			(96,904)	(95,754)
Interest on mandatorily redeemable preferred OP units / equity	(1,142)	(790)			(2,551)	(2,361)
Catastrophic weather related charges	173	7,718			(2,206)	8,075
Other income / (expense), net	1,230	3,345			(3,215)	5,341
Current tax (expense) / benefit	(135)	210			(366)	145
Deferred tax benefit	199	81			434	745
Net income	56,568	36,495			125,885	89,329
Less: Preferred return to Series A-1 preferred OP units	1,152	1,112			3,335	3,482
Less: Amounts attributable to noncontrolling interests	4,304	2,169			9,204	5,148
Net income attributable to Sun Communities, Inc.	51,112	33,214			113,346	80,699
Less: Preferred stock distributions	432	1,955			1,305	6,233
Net income attributable to Sun Communities, Inc. common stockholders	50,680	31,259			112,041	74,466
Home Sales and Home Rentals Segment [Member]
Segment Reporting Information [Line Items]
Revenues	59,720	45,954			162,205	129,093
Operating expenses/Cost of sales	39,831	31,869			107,772	84,820
Net operating income/Gross profit	19,889	14,085			54,433	44,273
Interest and other revenues, net	0	0			0	0
Home selling expenses	(4,043)	(3,290)			(11,319)	(9,391)
General and administrative	(2,940)	(2,497)			(8,466)	(6,830)
Transaction costs	0	(14)			0	(11)
Depreciation and amortization	(17,677)	(15,608)			(50,568)	(45,576)
Loss on extinguishment of debt	0	0			0	0
Interest	(5)	(3)			(15)	(11)
Interest on mandatorily redeemable preferred OP units / equity	0	0			0	0
Catastrophic weather related charges	0	38			219	49
Other income / (expense), net	1	0			1	(1)
Current tax (expense) / benefit	(78)	(172)			(246)	(278)
Deferred tax benefit	0	0			0	0
Net income	(4,853)	(7,537)			(16,399)	(17,852)
Less: Preferred return to Series A-1 preferred OP units	0	0			0	0
Less: Amounts attributable to noncontrolling interests	(233)	(393)			(812)	(969)
Net income attributable to Sun Communities, Inc.	(4,620)	(7,144)			(15,587)	(16,883)
Less: Preferred stock distributions	0	0			0	0
Net income attributable to Sun Communities, Inc. common stockholders	$ (4,620)	$ (7,144)			$ (15,587)	$ (16,883)

Segment Reporting Identifiable

Segment Reporting Identifiable Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	$ 6,053,977	$ 5,645,354
Cash and cash equivalents	113,556	10,127	$ 137,448	$ 8,164
Inventory of manufactured homes	41,030	30,430
Notes and other receivables, net	167,698	163,496
Collateralized receivables, net	112,228	128,246
Other assets	165,237	134,304
TOTAL ASSETS	6,653,726	6,111,957
Real Property Operations Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	5,534,397	5,172,521
Cash and cash equivalents	86,857	(7,649)
Inventory of manufactured homes	0	0
Notes and other receivables, net	149,564	149,798
Collateralized receivables, net	112,228	128,246
Other assets	138,451	130,455
TOTAL ASSETS	6,021,497	5,573,371
Home Sales and Home Rentals Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	519,580	472,833
Cash and cash equivalents	26,699	17,776
Inventory of manufactured homes	41,030	30,430
Notes and other receivables, net	18,134	13,698
Collateralized receivables, net	0	0
Other assets	26,786	3,849
TOTAL ASSETS	$ 632,229	$ 538,586

Income Taxes , Narrative (Detai

Income Taxes , Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating Loss Carryforwards [Line Items]
Minimum Percent of Income From Qualifying Sources to Allow For Real Estate Investment Trust Classification			95.00%
Required Minimum Percent of Taxable Income Distributed to Stock Holders			90.00%
Provision for state income taxes	$ 200	$ 38	$ (612)	$ (133)
Deferred tax benefit	199	$ 81	434	$ 745
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Liabilities, Gross	$ 21,300		$ 21,300

Earnings Per Share , Calculatio

Earnings Per Share , Calculation of Numerator and Denominator (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator
Net income attributable to common stockholders	$ 46,060	$ 24,115	$ 96,454	$ 57,583
Allocation to restricted stock awards	(396)	(189)	(830)	(461)
Basic earnings: Net income attributable to common stockholders after allocation	45,664	23,926	95,624	57,122
Allocation to restricted stock awards	396	189	0	461
Diluted earnings: Net income attributable to common stockholders after allocation	$ 46,060	$ 24,115	$ 95,624	$ 57,583
Denominator
Weighted average common shares outstanding	81,599	78,369	80,022	75,234
Add: dilutive stock options	2	2	2	2
Add: dilutive restricted stock	480	437	0	610
Diluted weighted average common shares and securities	82,081	78,808	80,024	75,846
Basic	$ 0.56	$ 0.31	$ 1.19	$ 0.76
Diluted	$ 0.56	$ 0.31	$ 1.19	$ 0.76

Earnings Per Share , Antidiluti

Earnings Per Share , Antidilutive Securities Excluded from Computation of Loss Per Share (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	6,172	6,256
Common OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,729	2,757
Series A-1 Preferred OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	332	349
Series A-3 Preferred OP Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	40	40
Series A-4 preferred OP units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	410	425
Series A-4 Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	1,063	1,085
Series C preferred OP units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	314	316
Aspen Preferred OP Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	1,284	1,284

Fair Value of Financial Instr_3

Fair Value of Financial Instruments , By Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financial assets
Notes and other receivables, net	$ 167,698	$ 163,496
Collateralized receivables, net	112,228	128,246
Financial liabilities
Secured debt	2,819,225	2,867,356
Lines of credit		41,257
Reported Value Measurement [Member]
Financial liabilities
Debt (excluding secured borrowings)	2,891,840	2,908,799
Lines of credit		41,257
Other liabilities (contingent consideration)	7,261	6,976
Reported Value Measurement [Member] | Installment notes receivable on manufactured homes, net [Member]
Financial assets
Notes and other receivables, net		115,797
Reported Value Measurement [Member] | Collateralized Receivables [Member]
Financial assets
Notes and other receivables, net	112,200	128,246
Reported Value Measurement [Member] | Secured Debt [Member]
Financial liabilities
Secured borrowings on collateralized receivables		129,182
Secured debt	113,089	129,182
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
Financial liabilities
Debt (excluding secured borrowings)	2,798,537	2,726,770
Secured borrowings on collateralized receivables	113,089
Secured debt		129,182
Lines of credit	0
Lines of credit		41,257
Other liabilities (contingent consideration)	7,261	6,976
Estimate of Fair Value Measurement [Member] | Installment notes receivable on manufactured homes, net [Member] | Fair Value, Measurements, Recurring [Member]
Financial assets
Notes and other receivables, net	117,583
Receivables		115,797
Estimate of Fair Value Measurement [Member] | Collateralized Receivables [Member] | Fair Value, Measurements, Recurring [Member]
Financial assets
Receivables		$ 128,246
Collateralized receivables, net	$ 112,228

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Accounting Changes and Error Corrections [Abstract]
Cash and cash equivalents	$ 113,556	$ 10,127	$ 137,448	$ 8,164
Restricted cash	15,538	13,382	19,943	17,149
Cash, cash equivalents and restricted cash	$ 129,094	$ 23,509	$ 157,391	$ 25,313

Commitments And Contingencies C

Commitments And Contingencies Commitments And Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Loss Contingency Accrual [Roll Forward]
Total estimated insurance receivable - December 31, 2017			$ 23,700
Change in estimated insurance recoveries			8,900
Advances from insurer			(16,400)
Total estimated insurance receivable - September 30, 2018	$ 16,200		16,200
Catastrophic weather related charges	$ (173)	$ (7,756)	$ (1,987)	$ (8,124)

Subsequent Event (Details)

Subsequent Event (Details) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 25, 2018USD ($)development_site	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)development_site	Dec. 31, 2017development_site
Subsequent Event [Line Items]
Payments to Acquire Land | $		$ 8	$ 7.5
Development Sites | development_site			1,166	18
Oak Creek | Subsequent Event
Subsequent Event [Line Items]
Payments to Acquire Land | $	$ 4.2
Development Sites | development_site	220