Hannon Armstrong Sustainable Infrastructure Capital (HASI) 10-Q 3 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	HASI
Entity Registrant Name	Hannon Armstrong Sustainable Infrastructure Capital, Inc.
Entity Central Index Key	1,561,894
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		53,067,158

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
Financing receivables	$ 1,062,051	$ 1,042,237
Investments	130,540	58,058
Real estate	313,642	172,257
Equity method investments	540,150	363,297
Cash and cash equivalents	90,752	29,428
Other assets	173,550	80,610
Total Assets	2,310,685	1,745,887
Liabilities:
Accounts payable, accrued expenses and other	33,187	25,219
Deferred funding obligations	225,817	170,892
Credit facilities	174,742	283,346
Non-recourse debt (secured by assets of $1,416 million and $864 million, respectively)	1,076,326	692,091
Convertible notes	145,914
Total Liabilities	1,655,986	1,171,548
Stockholders' Equity:
Preferred stock, par value $0.01 per share, 50,000,000 shares authorized, no shares issued and outstanding
Common stock, par value $0.01 per share, 450,000,000 shares authorized, 51,656,224 and 46,493,155 shares issued and outstanding, respectively	517	465
Additional paid in capital	768,665	663,744
Accumulated deficit	(117,122)	(92,213)
Accumulated other comprehensive income (loss)	(1,009)	(1,388)
Non-controlling interest	3,648	3,731
Total Stockholders' Equity	654,699	574,339
Total Liabilities and Stockholders' Equity	$ 2,310,685	$ 1,745,887

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Nonrecourse notes, secured by assets	$ 1,416	$ 864
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, shares issued	51,656,224	46,493,155
Common stock, shares outstanding	51,656,224	46,493,155

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue:
Interest income, financing receivables	$ 15,374	$ 12,043	$ 43,129	$ 36,178
Interest income, investments	1,316	494	3,617	1,303
Rental income	5,286	2,977	14,259	8,768
Gain on sale of receivables and investments	3,529	2,724	15,204	13,665
Fee income	897	770	2,268	1,422
Total Revenue	26,402	19,008	78,477	61,336
Expenses:
Interest expense	17,584	10,635	46,728	32,945
Compensation and benefits	5,347	4,325	15,732	14,497
General and administrative	2,367	1,991	7,694	6,129
Total Expenses	25,298	16,951	70,154	53,571
Income (loss) before equity method investments	1,104	2,057	8,323	7,765
Income (loss) from equity method investments	6,876	1,331	19,424	2,677
Income (loss) before income taxes	7,980	3,388	27,747	10,442
Income tax (expense) benefit	(5)	(41)	(119)	(123)
Net income (loss)	7,975	3,347	27,628	10,319
Net income (loss) attributable to non-controlling interest holders	42	18	156	75
Net income (loss) attributable to controlling stockholders	$ 7,933	$ 3,329	$ 27,472	$ 10,244
Basic earnings per common share	$ 0.14	$ 0.07	$ 0.52	$ 0.23
Diluted earnings per common share	$ 0.14	$ 0.07	$ 0.52	$ 0.23
Weighted average common shares outstanding-basic	51,655,868	41,988,036	49,924,224	38,924,977
Weighted average common shares outstanding-diluted	51,655,868	41,988,036	49,924,224	38,924,977

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 7,975	$ 3,347	$ 27,628	$ 10,319
Unrealized gain (loss) on interest rate swaps, net of tax benefit (provision) of $0.0 million in each of the three and nine month periods ended September 30, 2017 and 2016, respectively	(670)	488	(2,475)	(5,428)
Unrealized gain (loss) on available-for-sale securities, net of tax benefit (provision) of $0.0 million in each of the three and nine months periods ended September 30, 2017 and 2016, respectively	(47)	2,065	2,575	3,027
Comprehensive income (loss)	7,258	5,900	27,728	7,918
Less: Comprehensive income (loss) attributable to non-controlling interest holders	38	38	156	58
Comprehensive income (loss) attributable to controlling stockholders	$ 7,220	$ 5,862	$ 27,572	$ 7,860

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Unrealized gain (loss) on interest rate swaps, tax benefit (provision)	$ 0	$ 0	$ 0	$ 0
Unrealized gain (loss) on available-for-sale securities, benefit (provision)	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income (loss)	$ 27,628	$ 10,319
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,527	5,350
Equity-based compensation	8,351	7,452
Equity method investments	(10,725)	570
Non-cash gain on securitization	(18,136)	(8,730)
Gain on sale of financing receivables and investments	1,547	(1,589)
Changes in financing receivables held-for-sale		40,560
Changes in accounts payable and accrued expenses	1,218	4,596
Other	2,048	(7,523)
Net cash provided by operating activities	21,458	51,005
Cash flows from investing activities
Purchases of financing receivables	(86,637)	(223,051)
Principal collections from financing receivables	88,932	104,741
Proceeds from sales of financing receivables	79,175	35,052
Purchases of investments	(15,119)	(25,895)
Principal collections from investments	1,175	1,406
Proceeds from sales of investments		13,914
Purchases of real estate	(142,952)	(10,964)
Equity method investments	(229,800)	(14,165)
Equity method distributions received	57,545	41,800
Proceeds from sales of equity method investments	6,044
Funding of escrow accounts	(30,999)
Withdrawal from escrow accounts	1,919
Other	(459)	(1,070)
Net cash used in investing activities	(271,176)	(78,232)
Cash flows from financing activities
Proceeds from credit facilities	277,612	270,900
Principal payments on credit facilities	(386,234)	(161,275)
Proceeds from issuance of non-recourse debt	428,653
Principal payments on non-recourse debt	(46,120)	(56,324)
Proceeds from issuance of convertible notes	150,000
Payments on deferred funding obligations	(104,225)	(56,281)
Net proceeds from issuance of common stock	98,316	91,167
Payments of dividends and distributions	(50,628)	(36,401)
Other	(17,316)	(6,123)
Net cash provided by (used in) financing activities	350,058	45,663
Increase (decrease) in cash, cash equivalents, and restricted cash	100,340	18,436
Cash, cash equivalents, and restricted cash at beginning of period	59,144	79,216
Cash, cash equivalents, and restricted cash at end of period	159,484	97,652
Interest paid	32,929	28,056
Non-cash changes in deferred funding obligations	157,851	11,861
Non-cash changes in financing receivables and investments	(157,851)	(25,047)
Non-cash changes in residual assets	$ (18,136)	$ (8,730)

The Company

The Company	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The Company Hannon Armstrong Sustainable Infrastructure Capital, Inc. (the “Company”) makes debt and equity investments in sustainable infrastructure, including energy efficiency and renewable energy. The Company and its subsidiaries are hereafter referred to as “we,” “us,” or “our.” We refer to the financings that we hold on our balance sheet as our “Portfolio.” Our Portfolio may include: • Financing receivables, such as project loans and receivables, • Investments, such as debt securities, • Real estate, such as land or other physical assets and related intangible assets used in sustainable infrastructure projects, and • Equity investments in unconsolidated entities, such as projects where we hold a non-controlling We finance our business through cash on hand, borrowings under credit facilities and debt transactions, various asset-backed securitization transactions and equity issuances. We also generate fee income through securitizations and syndications, by providing broker/dealer services and by servicing assets owned by third parties. Some of our subsidiaries are special purpose entities that are formed for specific operations associated with financing sustainable infrastructure receivables for specific long term contracts. Our common stock is listed on the New York Stock Exchange (“NYSE”) under the symbol “HASI.” We have qualified as a REIT and also intend to operate our business in a manner that will continue to permit us to maintain our exception from registration as an investment company under the 1940 Act, as amended. We operate our business through, and serve as the sole general partner of, our operating partnership subsidiary, Hannon Armstrong Sustainable Infrastructure, L.P, (the “Operating Partnership”), which was formed to acquire and directly or indirectly own our assets.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The preparation of financial statements in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and such differences could be material. These financial statements have been prepared in accordance with the instructions to Form 10-Q 10-K No. 2016-18 Statement of Cash Flows (Topic 230). 10-K The consolidated financial statements include our accounts and controlled subsidiaries, including the Operating Partnership. All significant intercompany transactions and balances have been eliminated in consolidation. Financing Receivables Financing receivables include financing energy efficiency and renewable energy project loans and receivables. Unless otherwise noted, we generally have the ability and intent to hold our financing receivables for the foreseeable future and thus they are classified as held for investment. Our ability and intent to hold certain financing receivables may change from time to time depending on a number of factors, including economic, liquidity and capital market conditions. At inception of the arrangement, the carrying value of financing receivables held for investment represents the present value of the note, lease or other payments, net of any unearned fee income, which is recognized as income over the term of the note or lease using the effective interest method. Financing receivables that are held for investment are carried, unless deemed impaired, at amortized cost, net of any unamortized acquisition premiums or discounts and include origination and acquisition costs, as applicable. Our initial investment and principal repayments of these financing receivables are classified as investing activities and the interest collected is classified as operating activities in our statements of cash flows. Financing receivables that we intend to sell in the short-term are classified as held-for-sale held-for-sale We evaluate our financing receivables for potential delinquency or impairment on at least a quarterly basis and more frequently when economic or other conditions warrant such an evaluation. When a financing receivable becomes 90 days or more past due, and if we otherwise do not expect the debtor to be able to service all of its debt or other obligations, we will generally consider the financing receivable delinquent or impaired and place the financing receivable on non-accrual non-accrual A financing receivable is also considered impaired as of the date when, based on current information and events, it is determined that it is probable that we will be unable to collect all amounts due in accordance with the original contracted terms. Many of our financing receivables are secured by energy efficiency and renewable energy infrastructure projects. Accordingly, we regularly evaluate the extent and impact of any credit deterioration associated with the performance and value of the underlying project, as well as the financial and operating capability of the borrower, its sponsors or the obligor as well as any guarantors. We consider a number of qualitative and quantitative factors in our assessment, including, as appropriate, a project’s operating results, loan-to-value If a financing receivable is considered to be impaired, we will determine if an allowance should be recorded. We will record an allowance if the present value of expected future cash flows discounted at the financing receivable’s contractual effective rate is less than its carrying value. This estimate of cash flows may include the currently estimated fair market value of the collateral less estimated selling costs if repayment is expected solely from the collateral. We charge off financing receivables against the allowance, if any, when we determine the unpaid principal balance is uncollectible, net of recovered amounts. Investments Investments include debt securities that meet the criteria of Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 320, Investments—Debt and Equity Securities available-for-sale available-for-sale We evaluate our investments for OTTI on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Our OTTI assessment is a subjective process requiring the use of judgments and assumptions. Accordingly, we regularly evaluate the extent and impact of any credit deterioration associated with the financial and operating performance and value of the underlying project. We consider a number of qualitative and quantitative factors in our assessment. We first consider the current fair value of the security and the duration of any unrealized loss. Other factors considered include changes in the credit rating, performance of the underlying project, key terms of the transaction, the value of any collateral and any support provided by the sponsor or guarantor. To the extent that we have identified an OTTI for a security and intend to hold the investment to maturity and we do not expect that we will be required to sell the security prior to recovery of the amortized cost basis, we recognize only the credit component of the OTTI in earnings. We determine the credit component using the difference between the security’s amortized cost basis and the present value of its expected future cash flows, discounted using the effective interest method or its estimated collateral value. Any remaining unrealized loss due to factors other than credit is recorded in AOCI. To the extent we hold investments with an OTTI and if we have made the decision to sell the security or it is more likely than not that we will be required to sell the security prior to recovery of its amortized cost basis, we recognize the entire portion of the impairment in earnings. Premiums or discounts on investment securities are amortized or accreted into investment interest income using the effective interest method. Real Estate Real estate consists of land or other real estate and its related lease intangibles, net of any amortization. Our real estate is generally leased to tenants on a triple net lease basis, whereby the tenant is responsible for all operating expenses relating to the property, generally including property taxes, insurance, maintenance, repairs and capital expenditures. Scheduled rental revenue typically varies during the lease term and thus rental income is recognized on a straight-line basis, unless there is considerable risk as to collectability, so as to produce a constant periodic rent over the term of the lease. Accrued rental income is the aggregate difference between the scheduled rents which vary during the lease term and the income recognized on a straight-line basis and is recorded in other assets. Expenses related to leases where we are the lessor, if any, are charged to operations as incurred. Our initial investment is classified as investing activities and income collected for rental income is classified as operating activities in our statements of cash flows. We record our real estate purchases as asset acquisitions that are recorded at cost, including acquisition and closing costs, unless they meet the definition of a business combination in accordance with ASC 805, Business Combinations in-place The fair value of the tangible assets of an acquired leased property is determined by valuing the property as if it were vacant, and the “as-if-vacant” as-if-vacant In allocating the fair value of the identified intangibles of an acquired property, above-market and below-market in-place in-place in-place in-place Securitization of Receivables We have established various special purpose entities or securitization trusts for the purpose of securitizing certain financing receivables or other debt investments. We determined that the trusts used in securitizations are variable interest entities (“VIEs”), as defined in ASC 810, Consolidation We account for transfers of financing receivables to these securitization trusts as sales pursuant to ASC 860, Transfers and Servicing true-sale-at-law non-consolidation Gain or loss on the sale of receivables is calculated based on the excess of the proceeds received from the securitization (less any transaction costs) plus any retained interests obtained over the cost basis of the receivables sold. For retained interests, we generally estimate fair value based on the present value of future expected cash flows using our best estimates of the key assumptions of anticipated losses, prepayment rates, and current market discount rates commensurate with the risks involved. Cash flows related to our securitizations at origination are classified as operating activities in our statements of cash flows. We initially account for all separately recognized servicing assets and servicing liabilities at fair value and subsequently measure such servicing assets and liabilities using the amortization method. Servicing assets and liabilities are amortized in proportion to, and over the period of, estimated net servicing income with servicing income recognized as earned. We assess servicing assets for impairment at each reporting date. If the amortized cost of servicing assets is greater than the estimated fair value, we will recognize an impairment in net income. Our other retained interest in securitized assets, the residual assets, are classified as available-for-sale Cash and Cash Equivalents Cash and cash equivalents include short-term government securities, certificates of deposit and money market funds, all of which had an original maturity of three months or less at the date of purchase. These securities are carried at their purchase price, which approximates fair value. Restricted Cash Restricted cash includes cash and cash equivalents set aside with certain lenders primarily to support deferred funding and other obligations outstanding as of the balance sheet dates. Restricted cash is reported as part of other assets in the consolidated balance sheets. Refer to Note 3 for disclosure of the balances of restricted cash included in other assets. Consolidation and Equity Method Investments We account for our investments in entities that are considered voting interest entities or VIEs under ASC 810, Consolidation Substantially all of the activities of the special purpose entities that are formed for the purpose of holding our financing receivables and investments on our balance sheet are closely associated with our activities. Based on our assessment, we determined that we have power over and receive the benefits of these special purpose entities; hence, we are the primary beneficiary and should consolidate these entities under the provisions of ASC 810. We have made equity investments in various renewable energy projects. We share in the cash flows, income, and tax attributes according to a negotiated schedule (which typically does not correspond with our ownership percentages). Our renewable energy projects are typically owned in partnerships structures (using limited liability companies (“LLCs”), taxed as partnerships) where we receive a stated preferred return consisting of a priority distribution of all or a portion of the project’s cash flows, and in some cases, tax attributes. We have typically partnered with either the operator of the project or other institutional investors. Once our preferred return is achieved, the partnership “flips” and the company which operates the project, receives a larger portion of the cash flows through its interest in the holding company and we, along with any other institutional investors, will have an on-going These equity investments in renewable energy projects are accounted for under the equity method of accounting. Certain of our equity method investments were determined to be VIEs in which we are not the primary beneficiary. Our maximum exposure to loss associated with our equity method investments is limited to our recorded value of our investments. Under the equity method of accounting, the carrying value of these equity method investments is determined based on amounts we invested, adjusted for the equity in earnings or losses of the investee allocated based on the LLC agreement, less distributions received. Because certain of the LLC agreements contain preferences with regard to cash flows from operations, capital events and liquidation, we reflect our share of profits and losses by determining the difference between our “claim on the investee’s book value” at the end and the beginning of the period, which is adjusted for distributions received and contributions made. This claim is calculated as the amount we would receive (or be obligated to pay) if the investee were to liquidate all of its assets at recorded amounts determined in accordance with U.S. GAAP and distribute the resulting cash to creditors and investors in accordance with their respective priorities. This method is commonly referred to as the hypothetical liquidation at book value method or (“HLBV”). Intercompany gains and losses are eliminated for an amount equal to our interest and are reflected in our share of income or loss from equity method investments in the consolidated statements of operations. Cash distributions received from our equity method investments are classified as operating activities to the extent of cumulative HLBV earnings in our statements of cash flows. Our initial investment and additional cash distributions beyond that which is classified as operating activities are classified as investing activities in our statements of cash flows. We have elected to recognize earnings from these investments one quarter in arrears to allow for the receipt of financial information. We have also made an investment in a joint venture which holds land under solar projects that we have determined to be a voting interest entity. This investment entitles us to receive an equal percentage of both cash distributions and profit and loss under the terms of the LLC operating agreement. The investment is accounted for under the equity method of accounting, with our portion of income, being recognized in income (loss) from equity method investments in the period in which the income is earned. We evaluate on a quarterly basis whether our investments accounted for using the equity method have an OTTI. An OTTI occurs when the estimated fair value of an investment is below the carrying value and the difference is determined to not be recoverable. This evaluation requires significant judgment regarding, but not limited to, the severity and duration of the impairment; the ability and intent to hold the securities until recovery; financial condition, liquidity, and near-term prospects of the issuer; specific events; and other factors. Convertible Notes In August 2017, we issued convertible senior notes (“Convertible Notes”) that are accounted for in accordance with ASC 470-20, Debt with Conversion and Other Options Derivatives and Hedging. Derivative Financial Instruments We utilize derivative financial instruments, primarily interest rate swaps, to manage, or hedge, our interest rate risk exposures associated with new debt issuances, to manage our exposure to fluctuations in interest rates on variable rate debt, and to optimize the mix of our fixed and floating-rate debt. In addition, we use forward-starting interest rate swap contracts to manage a portion of our interest rate exposure for anticipated refinancing of our long-term debts. Our objective is to reduce the impact of changes in interest rates on our results of operations and cash flows. The fair values of our interest rate swaps designated and qualifying as effective cash flow hedges are reflected in our condensed consolidated balance sheets as a component of other assets (if in an unrealized asset position) or accounts payable, accrued expenses and other (if in an unrealized liability position) and in net unrealized gains and losses in AOCI. The cash settlements of our interest rate swaps are classified as operating activities in our statements of cash flows. The interest rate swaps we use are designated as cash flow hedges and are considered highly effective in reducing our exposure to the interest rate risk that they are designated to hedge. This effectiveness is required in order to qualify for hedge accounting. Instruments that meet the required hedging criteria are formally designated as hedges at the inception of the derivative contract. Derivatives are recorded at fair value. If a derivative is designated as a cash flow hedge and meets the highly effective threshold, the change in the fair value of the derivative is recorded in AOCI, net of associated deferred income tax effects and is recognized in earnings at the same time as the hedged item, including as a result of the accrual of interest. For any derivative instruments not designated as hedging instruments, changes in fair value would be recognized in earnings in the period that the change occurs. We assess, both at the inception of the hedge and on an ongoing basis, whether the derivatives designated as cash flow hedges are highly effective in offsetting the changes in cash flows of the hedged items. We do not hold derivatives for trading purposes. Interest rate swap contracts contain a credit risk that counterparties may be unable to fulfill the terms of the agreement. We attempt to minimize that risk by evaluating the creditworthiness of our counterparties, who are limited to major banks and financial institutions, and do not anticipate nonperformance by the counterparties. Income Taxes We elected and qualified to be taxed as a REIT for U.S. federal income tax purposes, commencing with our taxable year ended December 31, 2013. To qualify as a REIT, we must meet on an ongoing basis a number of organizational and operational requirements, including a requirement that we currently distribute at least 90% of our net taxable income, excluding capital gains, to our stockholders. We intend to continue to meet the requirements for qualification as a REIT. As a REIT, we are not subject to U.S. federal corporate income tax on that portion of net income that is currently distributed to our owners. However, our taxable REIT subsidiaries (“TRSs”) will generally be subject to U.S. federal, state, and local income taxes as well as taxes of foreign jurisdictions, if any. We account for income taxes under ASC 740, Income Taxes We apply ASC 740, Income Taxes Equity-Based Compensation In 2013, we adopted our equity incentive plan (the “2013 Plan”), which provides for grants of stock options, stock appreciation rights, restricted stock units, shares of restricted common stock, phantom shares, dividend equivalent rights, long-term incentive-plan units (“LTIP units”) and other restricted limited partnership units issued by our Operating Partnership and other equity-based awards. From time to time, we may make equity or equity based awards as compensation to members of our senior management team, our independent directors, employees, advisors, consultants and other personnel under our 2013 Plan. Certain awards earned under the plan are based on achieving various performance targets, which are generally earned between 0% and 200% of the initial target, depending on the extent to which the performance target is met. We record compensation expense for grants made under the 2013 Plan in accordance with ASC 718, Compensation—Stock Compensation Earnings Per Share We compute earnings per share of common stock in accordance with ASC 260, Earnings Per Share if-converted if-converted Segment Reporting We provide and arrange debt and equity investments for sustainable infrastructure projects and report all of our activities as one business segment. Recently Issued Accounting Pronouncements Revenue from Contracts with Customers In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers 2014-09 Leases In February 2016, the FASB issued ASU No. 2016-02, Leases right-of-use No. 2014-09, Revenue from Contracts with Customers pre-existing Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses—Measurement of Credit Losses on Financial Instruments 2016-13 2016-13 available-for-sale 2016-13 2016-13 Equity Method Investments In March 2016, the FASB issued ASU No. 2016-07, Simplifying the Transition to the Equity Method of Accounting Derivatives and Hedging In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities 2017-12 Other accounting standards updates effective after September 30, 2017, are not expected to have a material effect on our consolidated financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Fair value is defined as the price that would be received for an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. The fair value accounting guidance provides a three-level hierarchy for classifying financial instruments. The levels of inputs used to determine the fair value of our financial assets and liabilities carried on the balance sheet at fair value and for those which only disclosure of fair value is required are characterized in accordance with the fair value hierarchy established by ASC 820, Fair Value Measurements held-for-sale, • Level 1—Quoted prices (unadjusted) in active markets that are accessible at the measurement date. • Level 2—Observable prices that are based on inputs not quoted on active markets, but corroborated by market data. • Level 3—Unobservable inputs are used when little or no market data is available. The tables below illustrate the estimated fair value of our financial instruments on our balance sheet. Unless otherwise discussed below, fair value for our Level 2 and Level 3 measurements is measured using a discounted cash flow model, contractual terms and inputs which consist of base interest rates and spreads over base rates which are based upon market observation and recent comparable transactions. An increase in these inputs would result in a lower fair value and a decline would result in a higher fair value. Our convertible notes are valued using a market based approach and observable prices. The financing receivables held for sale, if any, are carried at the lower of cost or fair value. As of September 30, 2017 Fair Value Carrying Level (dollars in millions) Assets Financing receivables (1) $ 1,044 $ 1,062 Level 3 Investments (2) 131 131 Level 3 Securitization residual assets 35 35 Level 3 Liabilities Credit facilities $ 175 $ 175 Level 3 Non-recourse (3) 1,103 1,097 Level 3 Convertible notes (3) 156 151 Level 2 Derivative liabilities 1 1 Level 2 (1) There were no financing receivables held-for-sale as of September 30, 2017. (2) The amortized cost of our investments as of September 30, 2017 was $131 million. (3) Fair value and carrying value excludes unamortized debt issuance costs. As of December 31, 2016 Fair Value Carrying Level (dollars in millions) Assets Financing receivables (1) $ 1,017 $ 1,042 Level 3 Investments (2) 58 58 Level 3 Securitization residual assets 19 19 Level 3 Derivative assets 1 1 Level 2 Liabilities Credit facilities $ 283 $ 283 Level 3 Non-recourse (3) 718 709 Level 3 (1) There were no financing receivables held-for-sale as of December 31, 2016. (2) The amortized cost of our investments as of December 31, 2016 was $61 million. (3) Fair value and carrying value excludes unamortized debt issuance costs. Investments We carry our investments in debt securities at fair value on our balance sheet as investments. The following table reconciles the beginning and ending balances for our Level 3 investments that are carried at fair value on a recurring basis: For the three months For the nine months 2017 2016 2017 2016 (dollars in millions) Balance, beginning of period $ 126 $ 48 $ 58 $ 29 Purchases of investments 5 2 71 34 Payments on investments — — (1 ) (1 ) Sale of investments — — — (14 ) Realized gains on investments recorded in earnings — — — 1 Unrealized gains (losses) on investments recorded in OCI (1) — — 3 1 Balance, end of period $ 131 $ 50 $ 131 $ 50 (1) As of September 30, 2017 and December 31, 2016, approximately $10 million of investment grade rated debt was held for more than 12 months in an unrealized loss position of approximately $1 million due to interest rate movements. We have the intent and the ability to hold this investment until a recovery of amortized cost. As of September 30, 2017 and December 31, 2016, we held no other securities in an unrealized loss position for over 12 months. In determining the fair value of our investments, we used a range of interest rate spreads of approximately 1% to 4% based upon comparable transactions as of September 30, 2017 and December 31, 2016. Interest Rate Swap Agreements The fair values of the derivative financial instruments are determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. We have determined that the significant inputs, such as interest yield curves and discount rates, used to value our derivatives fall within Level 2 of the fair value hierarchy and that the credit valuation adjustments associated with our counterparties and our own credit risk utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of our or our counterparties default. As of September 30, 2017 and December 31, 2016, we assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and determined that the credit valuation adjustments were not significant to the overall valuation of our derivatives. As a result, we determined that our derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. The fair values of the derivative financial instruments are included in the other assets or accounts payable, accrued expenses and other line items in the consolidated balance sheets. Non-recurring Our financial statements may include non-recurring non-monetary Concentration of Credit Risk Financing receivables, investments and leases consist primarily of U.S. federal government-backed receivables, investment grade state and local government receivables and receivables from various sustainable infrastructure projects and do not, in our view, represent a significant concentration of credit risk. See Note 6 for an analysis by type of obligor. As described above, we do not believe we have a significant credit exposure to our interest rate swap providers. We had cash deposits that are subject to credit risk as shown below: September 30, December 31, (dollars in millions) Cash deposits $ 91 $ 29 Restricted cash deposits (included in other assets) 68 30 Total cash deposits $ 159 $ 59 Amount of cash deposits in excess of amounts federally insured $ 157 $ 57

Non-Controlling Interest

Non-Controlling Interest	9 Months Ended
	Sep. 30, 2017
Noncontrolling Interest [Abstract]
Non-Controlling Interest	4. Non-Controlling Units of limited partnership interests in the Operating Partnership (“OP units”) that are owned by limited partners other than us are included in non-controlling non-controlling

Securitization of Receivables

Securitization of Receivables	9 Months Ended
	Sep. 30, 2017
Transfers and Servicing [Abstract]
Securitization of Receivables	5. Securitization of Receivables The following summarizes certain transactions with our securitization trusts: As of and for the nine months 2017 2016 (dollars in millions) Gains on securitizations $ 15 $ 13 Purchase of receivables securitized $ 277 $ 394 Proceeds from securitizations $ 292 $ 407 Residual and servicing assets included in other assets $ 35 $ 18 Cash received from residual and servicing assets $ 4 $ 2 In connection with securitization transactions, we typically retain servicing responsibilities and residual assets. In certain instances, we receive annual servicing fees of up to 0.20% of the outstanding balance. We may periodically make servicer advances, which are subject to credit risk. Included in other assets in our consolidated balance sheets are our servicing assets at amortized cost, our residual assets at fair value, and our servicing advances at cost, if any. Our residual assets are subordinate to investors’ interests, and their values are subject to credit, prepayment and interest rate risks on the transferred financial assets. The investors and the securitization trusts have no recourse to our other assets for failure of debtors to pay when due. In computing gains and losses on securitizations, we use the same discount rates we use for the fair value calculation of residual assets, which are determined based on a review of comparable market transactions including Level 3 unobservable inputs which consist of base interest rates and spreads over base rates. Depending on the nature of the transaction risks, the discount rate ranged from 4% to 7%. As of September 30, 2017 and December 31, 2016, our managed assets totaled $4.6 billion and $3.9 billion, respectively, of which $2.5 billion and $2.3 billion, respectively, were securitized assets held in unconsolidated securitization trusts. There were no securitization credit losses in the nine months ended September 30, 2017 or 2016. As of September 30, 2017, there was approximately $1.8 million in payments from certain debtors to the securitization trusts that was greater than 90 days past due. The securitized assets consist of financing receivables from contracts for the installation of energy efficiency and other technologies in facilities owned by, or operated for or by, federal, state or local government entities where the ultimate obligor is the government. The contracts may have guarantees of energy savings from third party service providers, which typically are entities rated investment grade by an independent rating agency. Based on the nature of the receivables and experience-to-date,

Our Portfolio

Our Portfolio	9 Months Ended
	Sep. 30, 2017
Asset Retirement Obligation Disclosure [Abstract]
Our Portfolio	6. Our Portfolio As of September 30, 2017, our Portfolio included approximately $2.0 billion of financing receivables, investments, real estate and equity method investments on our balance sheet. The financing receivables and investments are typically collateralized by contractually committed debt obligations of government entities or private high credit quality obligors and are often supported by additional forms of credit enhancement, including security interests and supplier guaranties. The real estate is typically land and related lease intangibles for long-term leases to wind and solar projects with high credit quality obligors. The equity method investments represent our non-controlling The following is an analysis of our Portfolio by type of obligor and credit quality as of September 30, 2017: Investment Grade Government (1) Commercial (2) Commercial Non-Investment (3) Subtotal, Equity Method Total (dollars in millions) Financing receivables $ 574 $ 478 $ 10 $ 1,062 $ — $ 1,062 Investments 105 26 — 131 — 131 Real estate (4) — 314 — 314 21 335 Equity investments in renewable energy projects — — — — 519 519 Total $ 679 $ 818 $ 10 $ 1,507 $ 540 $ 2,047 % of Debt and real estate portfolio 45 % 54 % 1 % 100 % N/A N/A Average remaining balance (5) $ 12 $ 9 $ 5 $ 10 $ 20 $ 12 (1) Transactions where the ultimate obligor is the U.S. federal government or state or local governments where the obligors are rated investment grade (either by an independent rating agency or based upon our internal credit analysis). This amount includes $474 million of U.S. federal government transactions and $205 million of transactions where the ultimate obligors are state or local governments. Transactions may have guaranties of energy savings from third party service providers, which typically are entities rated investment grade by an independent rating agency. (2) Transactions where the projects or the ultimate obligors are commercial entities that have been rated investment grade (either by an independent rating agency or based on our internal credit analysis). Of this total, $10 million of the transactions have been rated investment grade by an independent rating agency. Commercial investment grade financing receivables include $310 million of internally rated residential solar loans made on a non-recourse (3) Transactions where the projects or the ultimate obligors are commercial entities that have ratings below investment grade (either by an independent rating agency or using our internal credit analysis). (4) Includes the real estate and the lease intangible assets (including those held through equity method investments) from which we receive scheduled lease payments, typically under long-term triple net lease agreements. (5) Excludes approximately 130 transactions each with outstanding balances that are less than $1 million and that in the aggregate total $51 million. Financing Receivables and Investments The following table provides a summary of our anticipated maturity dates of our financing receivables and investments and the weighted average yield for each range of maturities as of September 30, 2017: Total Less than 1 1-5 years 5-10 years More than 10 (dollars in millions) Financing Receivables Maturities by period $ 1,062 $ 4 $ 23 $ 77 $ 958 Weighted average yield by period 5.2 % 8.7 % 5.2 % 4.9 % 5.2 % Investments Maturities by period $ 131 $ — $ 66 $ 1 $ 64 Weighted average yield by period 3.9 % — % 3.6 % 4.7 % 4.3 % Our non-investment non-accrual Other than discussed above, we had no financing receivables, investments or leases that were impaired or on non-accrual Real Estate Our real estate is leased to renewable energy projects, typically under long-term triple net leases with expiration dates that range between the years 2033 and 2057 under the initial terms and 2047 and 2080 if all renewals are exercised. The components of our real estate portfolio as of September 30, 2017 and December 31, 2016, were as follows: September 30, December 31, (dollars in millions) Real Estate Land $ 226 $ 145 Lease intangibles 92 29 Accumulated amortization of lease intangibles (4 ) (2 ) Real Estate $ 314 $ 172 In the first quarter of 2017, we purchased a portfolio of over 4,000 acres of land and related long-term triple net leases to over 20 individual solar projects with investment grade off-takers As of September 30, 2017, the future amortization expense of these intangible assets and the future minimum rental income payments under our land lease agreements are as follows: Years Ending December 31, Future Minimum (dollars in millions) From October 1, 2017 to December 31, 2017 $ 1 $ 4 2018 3 18 2019 3 18 2020 3 18 2021 3 18 2022 3 19 Thereafter 72 674 Total $ 88 $ 769 There are conservation easement agreements covering several of our properties that limit the use of the property upon its lease expiration. Equity Investments We have made non-controlling Acquisition Date Transaction Investment Partner (dollars in millions) Various Vento I, LLC $ 121 EDP Renewables June 2017 Northern Frontier, LLC 87 Various December 2015 Buckeye Wind Energy Class B Holdings, LLC 67 Invenergy February 2017 Strong Upwind Holdings IV, LLC 56 JPMorgan October 2016 Invenergy Gunsight Mountain Holdings, LLC 36 Invenergy June 2016 MM Solar Holdings, LLC 29 AES Various Other transactions 144 Various Total Equity Method Investments $ 540 An underlying solar project associated with one of our equity method investments located in the U.S. Virgin Islands was materially damaged in the recent hurricanes. Although there can be no assurance in this regard, we believe that the project’s insurance will be sufficient to rebuild the project or to recover our investment in the project of approximately $10 million. Based on an evaluation of our equity method investments, inclusive of this project, we determined that no OTTI had occurred as of September 30, 2017, or December 31, 2016 Deferred Funding Obligations In accordance with the terms of certain purchase agreements relating to financing receivables and investments, payments of the purchase price are scheduled to be made over time and as a result, we have recorded deferred funding obligations of $226 million and $171 million as of September 30, 2017 and December 31, 2016, respectively. We have secured financing for, or placed in escrow, approximately $165 million of the deferred funding obligations as of September 30, 2017. As of September 30, 2017 and December 31, 2016, we have pledged approximately $29 million and $41 million of our equity method investments as collateral for a deferred funding obligation of $20 million and $34 million, respectively. The next five years of outstanding deferred funding obligations to be paid are as follows: (dollars in millions) October 1, 2017 to December 31, 2017 $ 29 2018 80 2019 69 2020 36 2021 12 Total Deferred funding obligations $ 226

Credit Facilities

Credit Facilities	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Credit Facilities	7. Credit Facilities Revolver We have a senior secured revolving credit facility which matures in July 2019. The facility provides for total maximum advances of $1.5 billion with the aggregate amount outstanding at any point in time of $500 million and which consists of two components, the “G&I Facility” and the “PF Facility”. The G&I Facility can be used to leverage certain qualifying government and institutional financings entered into by us and the PF Facility can be used to leverage certain qualifying project financings entered into by us. In June 2017, we entered into an amendment that adjusted certain of the sub-limits The following table provides additional detail on our credit facility as of September 30, 2017 and December 31, 2016: September 30, December 31, (dollars in millions) Outstanding balance $ 133 $ 283 Value of collateral pledged to credit facility $ 272 $ 471 Weighted average short-term borrowing rate 3.0 % 2.3 % Loans under the G&I Facility bear interest at a rate equal to the London Interbank Offered Rate (“LIBOR”) plus 1.5% or, under certain circumstances, 1.5% plus the Base Rate. Loans under the PF Facility bear interest at a rate equal to LIBOR plus 2.5% or, under certain circumstances, 2.5% plus the Base Rate or as mutually agreed. The Base Rate is defined as the highest of (i) the Federal Funds Rate plus 0.5%, (ii) the rate of interest publicly announced by Bank of America from time to time as its “prime rate,” (iii) LIBOR plus 1.0% and (iv) zero. Under the PF Facility, we also have the option to borrow at a fixed rate of interest until the expiration of the credit facility in July 2019. The fixed rate is determined by agreement with the administrative agent and is based on the prevailing US SWAP rate of an equivalent term to the average-life of the fixed rate portion of the borrowing plus an agreed upon margin. The loans are made through wholly-owned special purpose subsidiaries (the “Borrowers”) and we have guaranteed the obligations of the Borrowers under the credit facility pursuant to (x) a Continuing Guaranty, dated July 19, 2013, and (y) a Limited Guaranty, dated July 19, 2013, both as amended and restated. Any financing we propose to be included in the borrowing base as collateral under the facility is subject to the approval of the administrative agent in its sole discretion and the payment of a placement fee. We may, with the consent of the administrative agent, borrow against new projects before such projects become Approved Financings (as defined in the PF Facility loan agreement) but after they have been pledged as collateral. The amount eligible to be drawn under the facility for purposes of financing such investments will be based on a discount to the value of each investment or an applicable valuation percentage. Under the G&I Facility, the applicable valuation percentage for non-delinquent We have approximately $5 million of remaining unamortized costs associated with the credit facility that have been capitalized and included in other assets on our balance sheet, and are being amortized on a straight-line basis over the term of the loan agreements. On each monthly payment date, the Borrowers shall also pay to the administrative agent, for the benefit of the lenders, certain availability fees for each loan agreement equal to 0.50%, divided by 360, multiplied by the excess of the available borrowing capacity under each component of the credit facility over the actual amount borrowed under such component. The credit facility contains terms, conditions, covenants, and representations and warranties that are customary and typical for a transaction of this nature, including various affirmative and negative covenants, and limitations on the incurrence of liens and indebtedness, investments, fundamental organizational changes, dispositions, changes in the nature of business, transactions with affiliates, use of proceeds and stock repurchases. We were in compliance with our covenants as of September 30, 2017 and December 31, 2016. The credit facility also includes customary events of default, including the existence of a default in more than 50% of underlying financings. The occurrence of an event of default may result in termination of the credit facility, acceleration of amounts due under the credit facility, and accrual of default interest at a rate of LIBOR plus 2.50% in the case of the G&I Facility and at a rate of LIBOR plus 5.00% in the case of the PF Facility. Term Loan In February 2017, we borrowed $102 million under a recourse credit facility, of which $42 million was still outstanding as of September 30, 2017. We repaid the loan in October 2017.

Long-term Debt

Long-term Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Long-term Debt	8. Long-term Debt Non-recourse We have outstanding the following asset-backed non-recourse Outstanding Balance Value of Assets Pledged September 30, December 31, Interest Maturity Date Anticipated September 30, December 31, Description of Assets Pledged HASI Sustainable Yield Bond 2013-1 $ 68 $ 75 2.79 % December 2019 $ 57 $ 87 $ 93 Financing receivables ABS Loan Agreement $ 79 $ 90 5.74 % September 2021 $ 17 $ 80 $ 97 Equity interest in Strong Upwind Holdings I, LLC HASI Sustainable Yield Bond 2015-1A $ 95 $ 97 4.28 % October 2034 $ — $ 137 $ 138 Financing receivables, real estate and real estate intangibles HASI Sustainable Yield Bond 2015-1B $ 14 $ — 5.41 % October 2034 $ — $ 137 $ — Class B Bond of HASI Sustainable Yield Bond 2015-1 HASI SYB Loan Agreement 2015-1 $ — (1) $ 74 $ — (1) (1) $ — (1) $ — (1) $ 96 Equity interest in Strong Upwind Holdings II and III, LLC, related interest rate swap 2017 Credit Agreement $ 198 $ — 3.55 % (2) June 2024 $ — $ 243 $ — Equity interests in Strong Upwind Holdings I, II, III, and IV LLC, and Northern Frontier, LLC HASI SYB Loan Agreement 2015-2 $ 37 $ 41 5.41 % (3) December 2023 $ — $ 67 $ 70 Equity interest in Buckeye Wind Energy Class B Holdings LLC, related interest rate swap HASI SYB Loan Agreement 2015-3 $ 146 $ 150 4.92 % December 2020 $ 127 $ 172 $ 175 Residential solar financing receivables, related interest rate swaps HASI SYB Loan Agreement 2016-1 $ 118 $ 98 4.37 % (3) November 2021 $ 101 $ 138 $ 114 Residential solar financing receivables, related interest rate swaps HASI SYB Trust 2016-2 $ 86 $ — 4.35 % April 2037 $ — $ 88 $ — Financing receivables 2017 Master Repurchase Agreement $ 37 $ — 3.96 % (3) July 2019 $ 31 $ 41 $ — Financing receivables and investments HASI ECON 101 Trust $ 134 $ — 3.57 % May 2041 $ — $ 139 $ — Financing receivables and investments Other non-recourse debt (4) $ 85 $ 84 2.26% - 2017 to 2046 $ — $ 224 $ 81 Financing receivables Debt issuance costs (5) $ (21 ) $ (17 ) Non-recourse (6) $ 1,076 $ 692 (1) This non-recourse re-financed (2) Interest rate represents the current period’s LIBOR based rate plus the spread. Under the terms of the 2017 Credit Agreement, this rate will become fixed upon the lender’s syndication of the loan, or the rate can be fixed at our option. (3) Interest rate represents the current period’s LIBOR based rate plus the spread. Also see the interest rate swap contracts shown in the table below, the value of which are not included in the book value of assets pledged or the interest rate of the debt instrument. (4) Other non-recourse (5) Excludes costs of approximately $2 million associated with the 2017 Master Repurchase Agreement that were recorded in other assets due to the nature of the costs. (6) The total collateral pledged against our non-recourse We have pledged the financed assets, and typically our interests in one or more parents or subsidiaries of the borrower that are legally separate bankruptcy remote special purpose entities as security for the non-recourse We have guaranteed the performance of the representations and warranties and other obligations of certain of our subsidiaries under certain of the debt agreements and provided an indemnity against certain losses from “bad acts” of such subsidiaries including fraud, failure to disclose a material fact, theft, misappropriation, voluntary bankruptcy or unauthorized transfers. In the case of the debt secured by certain of our renewable energy equity interests, we have also guaranteed the compliance of our subsidiaries with certain tax matters and certain obligations if our joint venture partners exercise their right to withdraw from our partnerships. The HASI Sustainable Yield Bond (“HASI SYB”) 2015-1 2015-1A, 2015-1B, non-recourse In connection with several of our non-recourse Notional Value as of Fair Value as of Base Rate Hedged September 30, December 31, September 30, December 31, Term HASI SYB Loan Agreement 2015-1 (1) 3 month Libor 1.55 % $ — $ 67 $ — $ — December 2015 to September 2021 HASI SYB Loan Agreement 2015-2 3 month Libor 1.52 % $ 36 $ 37 $ — $ — December 2015 to December 2018 HASI SYB Loan Agreement 2015-2 3 month Libor 2.55 % $ 29 $ 29 $ (0.3 ) $ (0.2 ) December 2018 to December 2024 HASI SYB Loan Agreement 2015-3 1 month Libor 2.34 % $ 119 $ 119 $ (0.1 ) $ 1.0 November 2020 to August 2028 HASI SYB Loan Agreement 2016-1 3 month Libor 1.88 % $ 119 $ 72 $ 0.1 $ 0.2 November 2016 to November 2021 HASI SYB Loan Agreement 2016-1 3 month Libor 2.73 % $ 107 $ 107 $ (1.0 ) $ — November 2021 to October 2032 Total $ 410 $ 431 $ (1.3 ) $ 1.0 (1) This interest rate swap was financially settled in June 2017. The total fair value of our derivatives relating to interest rate hedges that are effective in offsetting variable cash flows is reflected as unrealized gains or losses in AOCI and in other assets or accounts payable, accrued expenses and other in the condensed consolidated balance sheets. As of September 30, 2017 and December 31, 2016, all of our derivatives were designated as hedging instruments. The following is an analysis of the financial statement line item impacted by our cash flow hedges in our condensed consolidated statement of operations: Three months ended Nine months ended (dollars in thousands) 2017 2016 2017 2016 Total interest expense $ 17,584 $ 10,635 $ 46,728 $ 32,945 Impact of hedging $ 201 $ 253 $ 798 $ 1,042 Our future stated minimum maturities of non-recourse (dollars in millions) October 1, 2017 to December 31, 2017 $ 24 2018 51 2019 142 2020 178 2021 146 2022 21 Thereafter 535 $ 1,097 Deferred financing costs, net (21 ) Total non-recourse $ 1,076 The stated minimum maturities of non-recourse SunPower, which originated and services the residential solar leases that are the collateral for the HASI SYB Loan Agreement 2015-3 2016-1, debt-to-EBITDA debt-to-EBITDA The portfolios of residential solar leases are held in bankruptcy remote special purpose entities (“SPEs”) that are performing in line with our expectations and the SPEs, and not SunPower, are the source of repayment under our loans. SunPower has provided us certain limited indemnities and warranties and as servicer, provides various services including billing, monitoring payments by homeowners to a third-party lockbox and customer service. Our loan agreements included the same debt-to-EBITDA Convertible Senior Notes In August 2017, we issued $150 million aggregate principal amount ($145 million net of issuance costs) of 4.125% convertible senior notes due September 1, 2022 (“Convertible Notes”). Holders may convert any of their Convertible Notes into shares of our common stock at the applicable conversion rate at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, unless the Convertible Notes have been previously redeemed or repurchased by us. The Convertible Notes are senior unsecured obligations of ours and have an initial conversion rate of 36.7101 shares for each $1,000 principal amount of Convertible Notes which is equal to a total of approximately 5.5 million shares. The conversion rate is subject to adjustment for dividends declared above $.33 per share per quarter and certain other events that may be dilutive to the holder. As of September 30, 2017, none of these dilutive events have occurred and the conversion rate remains at the initial rate. Following the occurrence of a make-whole fundamental change, we will, in certain circumstances, increase the conversion rate for a holder that converts its Convertible Notes in connection with such make-whole fundamental change. There are no cash settlement provisions in the Convertible Notes and the conversion option can only be settled through physical delivery of our common stock. Additionally, upon the occurrence of certain fundamental changes involving us, holders of the Convertible Notes may require us to redeem all or a portion of their Convertible Notes for cash at a price of 100% of the principal amount outstanding, plus accrued and unpaid interest. We have a redemption option to call the Convertible Notes prior to maturity (i) on or after March 1, 2022 and (ii) at any time if such a redemption is deemed reasonably necessary to preserve our qualification as a REIT. The redemption price will be equal to the principal of the notes being redeemed, plus accrued and unpaid interest. In the event of redemption after March 1, 2022, there will be an additional make-whole premium paid to the holder of the redeemed notes unless the redemption is deemed reasonably necessary to preserve our qualification as a REIT. The following table presents a summary of the components of the Convertible Notes (dollars in millions): September 30, Principal $ 150 Accrued interest 1 Less: Unamortized financing costs (5 ) Carrying value of Convertible Notes $ 146 During the three and nine months ended September 30, 2017, we recorded $0.8 million in interest expense related to the Convertible Notes.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Litigation The nature of our operations exposes us to the risk of claims and litigation in the normal course of our business. Other than non-material

Income Tax

Income Tax	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Tax	10. Income Tax We recorded a tax expense of approximately $0.1 million for the nine months ended September 30, 2017 and 2016, and less than $0.1 million for the three months ended September 30, 2017 and 2016. Our income tax expense was determined using a federal rate of 35% and a combined state rate, net of federal benefit, of 5%.

Equity

Equity	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Equity	11. Equity Dividends and Distributions Our board of directors declared the following dividends in 2016 and 2017: Announced Date Record Date Pay Date Amount per 3/15/16 3/30/16 4/7/16 $ 0.30 6/07/16 7/06/16 7/14/16 $ 0.30 9/15/16 10/05/16 10/13/16 $ 0.30 12/13/16 12/29/16 (1) 1/12/17 $ 0.33 3/15/17 4/05/17 4/13/17 $ 0.33 6/01/17 7/06/17 7/13/17 $ 0.33 9/12/17 10/05/17 10/16/17 $ 0.33 (1) This dividend was treated as a distribution in 2017 for tax purposes. We have an effective universal shelf registration statement registering the potential offer and sale, from time to time and in one or more offerings, of any combination of our common stock, preferred stock, depositary shares, debt securities, warrants and rights (collectively referred to as the “securities”). We may offer the securities directly, through agents, or to or through underwriters by means of ordinary brokers’ transactions on the NYSE or otherwise at market prices prevailing at the time of sale or at negotiated prices and may include “at the market” (“ATM”) offerings or sales “at the market,” to or through a market maker or into an existing trading market on an exchange or otherwise. We completed the following public offerings and ATM offerings of our common stock in 2016 and 2017: Closing Date Common Stock Shares Issued (1) Price Net (2) (amounts in millions, except per share amounts) 6/21/16 Public Offering 4.600 $ 19.78 (3) $ 91 5/9/16 to 6/30/16 ATM 0.065 $ 20.31 (4) $ 1 11/09/16 Public Offering 4.025 $ 19.28 (3) $ 77 12/13/16 to 12/29/16 ATM 0.407 $ 19.47 (4) $ 8 1/20/17 to 2/2/17 ATM 0.197 $ 19.18 (4) $ 4 3/10/17 Public Offering 3.450 $ 18.73 (3) $ 64 5/17/17 to 6/22/17 ATM 1.376 $ 22.71 (4) $ 31 (1) Includes shares issued in connection with the exercise of the underwriters’ option to purchase additional shares. (2) Net proceeds from the offerings is shown after deducting underwriting discounts, commissions and other offering costs. (3) Represents the price per share at which the underwriters in our public offerings purchased our shares. (4) Represents the average price per share at which investors in our ATM offerings purchased our shares. Awards of Shares of Restricted Common Stock and Restricted Stock Units under our 2013 Plan We have issued awards with service, performance and market conditions. During the nine months ended September 30, 2017, our board of directors awarded employees and directors 707,648 shares of restricted stock and restricted stock units that vest from 2017 to 2021. As of September 30, 2017, as it relates to previously issued restricted stock awards with performance conditions, we have concluded that it is probable that the performance conditions will be met. For the three and nine months ended September 30, 2017, we recorded $3 million and $8 million, respectively, of equity-based compensation expense as compared to $3 million and $7 million, respectively, for the three and nine months ended September 30, 2016. The total unrecognized compensation expense related to awards of shares of restricted stock and restricted stock units was approximately $15 million as of September 30, 2017. We expect to recognize compensation expense related to these awards over a weighted-average term of approximately two years. A summary of the unvested shares of restricted common stock that have been issued is as follows: Restricted Weighted Average Value Ending Balance — December 31, 2015 1,248,069 $ 15.16 $ 18.9 Granted 661,055 18.62 12.3 Vested (716,264 ) 14.03 (10.0 ) Forfeited (11,188 ) 17.25 (0.2 ) Ending Balance — December 31, 2016 1,181,672 $ 17.76 $ 21.0 Granted 451,614 19.04 8.6 Vested (217,833 ) 14.15 (3.1 ) Forfeited (4,519 ) 18.72 (0.1 ) Ending Balance — September 30, 2017 1,410,934 $ 18.72 $ 26.4 A summary of the unvested shares of restricted stock units that have market based vesting conditions that have been issued is as follows: Restricted Stock (1) Weighted Average Value Ending Balance — December 31, 2016 — — — Granted 256,034 $ 18.99 $ 4.9 Vested (376 ) 18.99 — Forfeited (1,202 ) 18.99 — Ending Balance — September 30, 2017 254,456 $ 18.99 $ 4.9 (1) As discussed in Note 2 these restricted stock units vest between 0% and 200% of the target. The amounts shown represent the number of restricted stock units at 100% of target.

Earnings per Share of Common St

Earnings per Share of Common Stock	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings per Share of Common Stock	12. Earnings per Share of Common Stock Both the net income or loss attributable to the non-controlling non-controlling Unvested share-based payment awards that contain non-forfeitable two-class if-converted The computation of basic and diluted earnings per common share of common stock is as follows: Three Months Ended Nine Months Ended Numerator: 2017 2016 2017 2016 (in millions, except share and per share data) Net income attributable to controlling stockholders and participating securities $ 7.9 $ 3.3 $ 27.5 $ 10.2 Less: Dividends paid on participating securities (0.4 ) (0.4 ) (1.5 ) (1.3 ) Undistributed earnings attributable to participating securities — — — — Net income attributable to controlling stockholders $ 7.5 $ 2.9 $ 26.0 $ 8.9 Denominator: Weighted-average number of common shares — basic 51,655,868 41,988,036 49,924,224 38,924,977 Weighted-average number of common shares — diluted 51,655,868 41,988,036 49,924,224 38,924,977 Basic earnings per common share $ 0.14 $ 0.07 $ 0.52 $ 0.23 Diluted earnings per common share $ 0.14 $ 0.07 $ 0.52 $ 0.23 Other Information: Weighted-average number of OP units 284,992 284,992 284,992 284,992 Unvested restricted common stock outstanding as of 1,410,934 1,323,460 1,410,934 1,323,460 Unvested restricted stock units outstanding as of 254,456 — 254,456 —

Equity Method Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	13. Equity Method Investments We have non-controlling The following is a summary of the consolidated financial position and results of operations of the significant entities accounted for using the equity method. As of As of (dollars in millions, unaudited) Current assets $ 4 $ 3 Total assets $ 115 $ 99 Current liabilities $ 5 $ 4 Total liabilities $ 37 $ 39 Members’ equity $ 78 $ 60 For the six months 2017 2016 (dollars in millions, unaudited) Revenue $ 7 $ 6 Income from continuing operations $ 3 $ 1 Net income $ 3 $ 1

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The preparation of financial statements in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and such differences could be material. These financial statements have been prepared in accordance with the instructions to Form 10-Q 10-K No. 2016-18 Statement of Cash Flows (Topic 230). 10-K The consolidated financial statements include our accounts and controlled subsidiaries, including the Operating Partnership. All significant intercompany transactions and balances have been eliminated in consolidation.
Financing Receivables	Financing Receivables Financing receivables include financing energy efficiency and renewable energy project loans and receivables. Unless otherwise noted, we generally have the ability and intent to hold our financing receivables for the foreseeable future and thus they are classified as held for investment. Our ability and intent to hold certain financing receivables may change from time to time depending on a number of factors, including economic, liquidity and capital market conditions. At inception of the arrangement, the carrying value of financing receivables held for investment represents the present value of the note, lease or other payments, net of any unearned fee income, which is recognized as income over the term of the note or lease using the effective interest method. Financing receivables that are held for investment are carried, unless deemed impaired, at amortized cost, net of any unamortized acquisition premiums or discounts and include origination and acquisition costs, as applicable. Our initial investment and principal repayments of these financing receivables are classified as investing activities and the interest collected is classified as operating activities in our statements of cash flows. Financing receivables that we intend to sell in the short-term are classified as held-for-sale held-for-sale We evaluate our financing receivables for potential delinquency or impairment on at least a quarterly basis and more frequently when economic or other conditions warrant such an evaluation. When a financing receivable becomes 90 days or more past due, and if we otherwise do not expect the debtor to be able to service all of its debt or other obligations, we will generally consider the financing receivable delinquent or impaired and place the financing receivable on non-accrual non-accrual A financing receivable is also considered impaired as of the date when, based on current information and events, it is determined that it is probable that we will be unable to collect all amounts due in accordance with the original contracted terms. Many of our financing receivables are secured by energy efficiency and renewable energy infrastructure projects. Accordingly, we regularly evaluate the extent and impact of any credit deterioration associated with the performance and value of the underlying project, as well as the financial and operating capability of the borrower, its sponsors or the obligor as well as any guarantors. We consider a number of qualitative and quantitative factors in our assessment, including, as appropriate, a project’s operating results, loan-to-value If a financing receivable is considered to be impaired, we will determine if an allowance should be recorded. We will record an allowance if the present value of expected future cash flows discounted at the financing receivable’s contractual effective rate is less than its carrying value. This estimate of cash flows may include the currently estimated fair market value of the collateral less estimated selling costs if repayment is expected solely from the collateral. We charge off financing receivables against the allowance, if any, when we determine the unpaid principal balance is uncollectible, net of recovered amounts.
Investments	Investments Investments include debt securities that meet the criteria of Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 320, Investments—Debt and Equity Securities available-for-sale available-for-sale We evaluate our investments for OTTI on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Our OTTI assessment is a subjective process requiring the use of judgments and assumptions. Accordingly, we regularly evaluate the extent and impact of any credit deterioration associated with the financial and operating performance and value of the underlying project. We consider a number of qualitative and quantitative factors in our assessment. We first consider the current fair value of the security and the duration of any unrealized loss. Other factors considered include changes in the credit rating, performance of the underlying project, key terms of the transaction, the value of any collateral and any support provided by the sponsor or guarantor. To the extent that we have identified an OTTI for a security and intend to hold the investment to maturity and we do not expect that we will be required to sell the security prior to recovery of the amortized cost basis, we recognize only the credit component of the OTTI in earnings. We determine the credit component using the difference between the security’s amortized cost basis and the present value of its expected future cash flows, discounted using the effective interest method or its estimated collateral value. Any remaining unrealized loss due to factors other than credit is recorded in AOCI. To the extent we hold investments with an OTTI and if we have made the decision to sell the security or it is more likely than not that we will be required to sell the security prior to recovery of its amortized cost basis, we recognize the entire portion of the impairment in earnings. Premiums or discounts on investment securities are amortized or accreted into investment interest income using the effective interest method.
Real Estate	Real Estate Real estate consists of land or other real estate and its related lease intangibles, net of any amortization. Our real estate is generally leased to tenants on a triple net lease basis, whereby the tenant is responsible for all operating expenses relating to the property, generally including property taxes, insurance, maintenance, repairs and capital expenditures. Scheduled rental revenue typically varies during the lease term and thus rental income is recognized on a straight-line basis, unless there is considerable risk as to collectability, so as to produce a constant periodic rent over the term of the lease. Accrued rental income is the aggregate difference between the scheduled rents which vary during the lease term and the income recognized on a straight-line basis and is recorded in other assets. Expenses related to leases where we are the lessor, if any, are charged to operations as incurred. Our initial investment is classified as investing activities and income collected for rental income is classified as operating activities in our statements of cash flows. We record our real estate purchases as asset acquisitions that are recorded at cost, including acquisition and closing costs, unless they meet the definition of a business combination in accordance with ASC 805, Business Combinations in-place The fair value of the tangible assets of an acquired leased property is determined by valuing the property as if it were vacant, and the “as-if-vacant” as-if-vacant In allocating the fair value of the identified intangibles of an acquired property, above-market and below-market in-place in-place in-place in-place
Securitization of Receivables	Securitization of Receivables We have established various special purpose entities or securitization trusts for the purpose of securitizing certain financing receivables or other debt investments. We determined that the trusts used in securitizations are variable interest entities (“VIEs”), as defined in ASC 810, Consolidation We account for transfers of financing receivables to these securitization trusts as sales pursuant to ASC 860, Transfers and Servicing true-sale-at-law non-consolidation Gain or loss on the sale of receivables is calculated based on the excess of the proceeds received from the securitization (less any transaction costs) plus any retained interests obtained over the cost basis of the receivables sold. For retained interests, we generally estimate fair value based on the present value of future expected cash flows using our best estimates of the key assumptions of anticipated losses, prepayment rates, and current market discount rates commensurate with the risks involved. Cash flows related to our securitizations at origination are classified as operating activities in our statements of cash flows. We initially account for all separately recognized servicing assets and servicing liabilities at fair value and subsequently measure such servicing assets and liabilities using the amortization method. Servicing assets and liabilities are amortized in proportion to, and over the period of, estimated net servicing income with servicing income recognized as earned. We assess servicing assets for impairment at each reporting date. If the amortized cost of servicing assets is greater than the estimated fair value, we will recognize an impairment in net income. Our other retained interest in securitized assets, the residual assets, are classified as available-for-sale
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include short-term government securities, certificates of deposit and money market funds, all of which had an original maturity of three months or less at the date of purchase. These securities are carried at their purchase price, which approximates fair value.
Restricted Cash	Restricted Cash Restricted cash includes cash and cash equivalents set aside with certain lenders primarily to support deferred funding and other obligations outstanding as of the balance sheet dates. Restricted cash is reported as part of other assets in the consolidated balance sheets. Refer to Note 3 for disclosure of the balances of restricted cash included in other assets.
Consolidation and Equity Method Investments	Consolidation and Equity Method Investments We account for our investments in entities that are considered voting interest entities or VIEs under ASC 810, Consolidation Substantially all of the activities of the special purpose entities that are formed for the purpose of holding our financing receivables and investments on our balance sheet are closely associated with our activities. Based on our assessment, we determined that we have power over and receive the benefits of these special purpose entities; hence, we are the primary beneficiary and should consolidate these entities under the provisions of ASC 810. We have made equity investments in various renewable energy projects. We share in the cash flows, income, and tax attributes according to a negotiated schedule (which typically does not correspond with our ownership percentages). Our renewable energy projects are typically owned in partnerships structures (using limited liability companies (“LLCs”), taxed as partnerships) where we receive a stated preferred return consisting of a priority distribution of all or a portion of the project’s cash flows, and in some cases, tax attributes. We have typically partnered with either the operator of the project or other institutional investors. Once our preferred return is achieved, the partnership “flips” and the company which operates the project, receives a larger portion of the cash flows through its interest in the holding company and we, along with any other institutional investors, will have an on-going These equity investments in renewable energy projects are accounted for under the equity method of accounting. Certain of our equity method investments were determined to be VIEs in which we are not the primary beneficiary. Our maximum exposure to loss associated with our equity method investments is limited to our recorded value of our investments. Under the equity method of accounting, the carrying value of these equity method investments is determined based on amounts we invested, adjusted for the equity in earnings or losses of the investee allocated based on the LLC agreement, less distributions received. Because certain of the LLC agreements contain preferences with regard to cash flows from operations, capital events and liquidation, we reflect our share of profits and losses by determining the difference between our “claim on the investee’s book value” at the end and the beginning of the period, which is adjusted for distributions received and contributions made. This claim is calculated as the amount we would receive (or be obligated to pay) if the investee were to liquidate all of its assets at recorded amounts determined in accordance with U.S. GAAP and distribute the resulting cash to creditors and investors in accordance with their respective priorities. This method is commonly referred to as the hypothetical liquidation at book value method or (“HLBV”). Intercompany gains and losses are eliminated for an amount equal to our interest and are reflected in our share of income or loss from equity method investments in the consolidated statements of operations. Cash distributions received from our equity method investments are classified as operating activities to the extent of cumulative HLBV earnings in our statements of cash flows. Our initial investment and additional cash distributions beyond that which is classified as operating activities are classified as investing activities in our statements of cash flows. We have elected to recognize earnings from these investments one quarter in arrears to allow for the receipt of financial information. We have also made an investment in a joint venture which holds land under solar projects that we have determined to be a voting interest entity. This investment entitles us to receive an equal percentage of both cash distributions and profit and loss under the terms of the LLC operating agreement. The investment is accounted for under the equity method of accounting, with our portion of income, being recognized in income (loss) from equity method investments in the period in which the income is earned. We evaluate on a quarterly basis whether our investments accounted for using the equity method have an OTTI. An OTTI occurs when the estimated fair value of an investment is below the carrying value and the difference is determined to not be recoverable. This evaluation requires significant judgment regarding, but not limited to, the severity and duration of the impairment; the ability and intent to hold the securities until recovery; financial condition, liquidity, and near-term prospects of the issuer; specific events; and other factors.
Convertible Notes	Convertible Notes In August 2017, we issued convertible senior notes (“Convertible Notes”) that are accounted for in accordance with ASC 470-20, Debt with Conversion and Other Options Derivatives and Hedging.
Derivative Financial Instruments	Derivative Financial Instruments We utilize derivative financial instruments, primarily interest rate swaps, to manage, or hedge, our interest rate risk exposures associated with new debt issuances, to manage our exposure to fluctuations in interest rates on variable rate debt, and to optimize the mix of our fixed and floating-rate debt. In addition, we use forward-starting interest rate swap contracts to manage a portion of our interest rate exposure for anticipated refinancing of our long-term debts. Our objective is to reduce the impact of changes in interest rates on our results of operations and cash flows. The fair values of our interest rate swaps designated and qualifying as effective cash flow hedges are reflected in our condensed consolidated balance sheets as a component of other assets (if in an unrealized asset position) or accounts payable, accrued expenses and other (if in an unrealized liability position) and in net unrealized gains and losses in AOCI. The cash settlements of our interest rate swaps are classified as operating activities in our statements of cash flows. The interest rate swaps we use are designated as cash flow hedges and are considered highly effective in reducing our exposure to the interest rate risk that they are designated to hedge. This effectiveness is required in order to qualify for hedge accounting. Instruments that meet the required hedging criteria are formally designated as hedges at the inception of the derivative contract. Derivatives are recorded at fair value. If a derivative is designated as a cash flow hedge and meets the highly effective threshold, the change in the fair value of the derivative is recorded in AOCI, net of associated deferred income tax effects and is recognized in earnings at the same time as the hedged item, including as a result of the accrual of interest. For any derivative instruments not designated as hedging instruments, changes in fair value would be recognized in earnings in the period that the change occurs. We assess, both at the inception of the hedge and on an ongoing basis, whether the derivatives designated as cash flow hedges are highly effective in offsetting the changes in cash flows of the hedged items. We do not hold derivatives for trading purposes. Interest rate swap contracts contain a credit risk that counterparties may be unable to fulfill the terms of the agreement. We attempt to minimize that risk by evaluating the creditworthiness of our counterparties, who are limited to major banks and financial institutions, and do not anticipate nonperformance by the counterparties.
Income Taxes	Income Taxes We elected and qualified to be taxed as a REIT for U.S. federal income tax purposes, commencing with our taxable year ended December 31, 2013. To qualify as a REIT, we must meet on an ongoing basis a number of organizational and operational requirements, including a requirement that we currently distribute at least 90% of our net taxable income, excluding capital gains, to our stockholders. We intend to continue to meet the requirements for qualification as a REIT. As a REIT, we are not subject to U.S. federal corporate income tax on that portion of net income that is currently distributed to our owners. However, our taxable REIT subsidiaries (“TRSs”) will generally be subject to U.S. federal, state, and local income taxes as well as taxes of foreign jurisdictions, if any. We account for income taxes under ASC 740, Income Taxes We apply ASC 740, Income Taxes
Equity-Based Compensation	Equity-Based Compensation In 2013, we adopted our equity incentive plan (the “2013 Plan”), which provides for grants of stock options, stock appreciation rights, restricted stock units, shares of restricted common stock, phantom shares, dividend equivalent rights, long-term incentive-plan units (“LTIP units”) and other restricted limited partnership units issued by our Operating Partnership and other equity-based awards. From time to time, we may make equity or equity based awards as compensation to members of our senior management team, our independent directors, employees, advisors, consultants and other personnel under our 2013 Plan. Certain awards earned under the plan are based on achieving various performance targets, which are generally earned between 0% and 200% of the initial target, depending on the extent to which the performance target is met. We record compensation expense for grants made under the 2013 Plan in accordance with ASC 718, Compensation—Stock Compensation
Earnings Per Share	Earnings Per Share We compute earnings per share of common stock in accordance with ASC 260, Earnings Per Share if-converted if-converted
Segment Reporting	Segment Reporting We provide and arrange debt and equity investments for sustainable infrastructure projects and report all of our activities as one business segment.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Revenue from Contracts with Customers In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers 2014-09 Leases In February 2016, the FASB issued ASU No. 2016-02, Leases right-of-use No. 2014-09, Revenue from Contracts with Customers pre-existing Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses—Measurement of Credit Losses on Financial Instruments 2016-13 2016-13 available-for-sale 2016-13 2016-13 Equity Method Investments In March 2016, the FASB issued ASU No. 2016-07, Simplifying the Transition to the Equity Method of Accounting Derivatives and Hedging In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities 2017-12 Other accounting standards updates effective after September 30, 2017, are not expected to have a material effect on our consolidated financial statements and related disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Fair Value and Carrying Value of Financial Assets and Liabilities	As of September 30, 2017 Fair Value Carrying Level (dollars in millions) Assets Financing receivables (1) $ 1,044 $ 1,062 Level 3 Investments (2) 131 131 Level 3 Securitization residual assets 35 35 Level 3 Liabilities Credit facilities $ 175 $ 175 Level 3 Non-recourse (3) 1,103 1,097 Level 3 Convertible notes (3) 156 151 Level 2 Derivative liabilities 1 1 Level 2 (1) There were no financing receivables held-for-sale as of September 30, 2017. (2) The amortized cost of our investments as of September 30, 2017 was $131 million. (3) Fair value and carrying value excludes unamortized debt issuance costs. As of December 31, 2016 Fair Value Carrying Level (dollars in millions) Assets Financing receivables (1) $ 1,017 $ 1,042 Level 3 Investments (2) 58 58 Level 3 Securitization residual assets 19 19 Level 3 Derivative assets 1 1 Level 2 Liabilities Credit facilities $ 283 $ 283 Level 3 Non-recourse (3) 718 709 Level 3 (1) There were no financing receivables held-for-sale as of December 31, 2016. (2) The amortized cost of our investments as of December 31, 2016 was $61 million. (3) Fair value and carrying value excludes unamortized debt issuance costs.
Schedule of Reconciliation of Level 3 Investments Securities	The following table reconciles the beginning and ending balances for our Level 3 investments that are carried at fair value on a recurring basis: For the three months For the nine months 2017 2016 2017 2016 (dollars in millions) Balance, beginning of period $ 126 $ 48 $ 58 $ 29 Purchases of investments 5 2 71 34 Payments on investments — — (1 ) (1 ) Sale of investments — — — (14 ) Realized gains on investments recorded in earnings — — — 1 Unrealized gains (losses) on investments recorded in OCI (1) — — 3 1 Balance, end of period $ 131 $ 50 $ 131 $ 50 (1) As of September 30, 2017 and December 31, 2016, approximately $10 million of investment grade rated debt was held for more than 12 months in an unrealized loss position of approximately $1 million due to interest rate movements. We have the intent and the ability to hold this investment until a recovery of amortized cost. As of September 30, 2017 and December 31, 2016, we held no other securities in an unrealized loss position for over 12 months.
Schedule of Cash Deposits Subject to Credit Risk	We had cash deposits that are subject to credit risk as shown below: September 30, December 31, (dollars in millions) Cash deposits $ 91 $ 29 Restricted cash deposits (included in other assets) 68 30 Total cash deposits $ 159 $ 59 Amount of cash deposits in excess of amounts federally insured $ 157 $ 57

Securitization of Receivables (

Securitization of Receivables (Tables)	9 Months Ended
	Sep. 30, 2017
Transfers and Servicing [Abstract]
Summary of Certain Transactions with Securitization Trusts	The following summarizes certain transactions with our securitization trusts: As of and for the nine months 2017 2016 (dollars in millions) Gains on securitizations $ 15 $ 13 Purchase of receivables securitized $ 277 $ 394 Proceeds from securitizations $ 292 $ 407 Residual and servicing assets included in other assets $ 35 $ 18 Cash received from residual and servicing assets $ 4 $ 2

Our Portfolio (Tables)

Our Portfolio (Tables)	9 Months Ended
	Sep. 30, 2017
Asset Retirement Obligation Disclosure [Abstract]
Analysis of Portfolio by Type of Obligor and Credit Quality	The following is an analysis of our Portfolio by type of obligor and credit quality as of September 30, 2017: Investment Grade Government (1) Commercial (2) Commercial Non-Investment (3) Subtotal, Equity Method Total (dollars in millions) Financing receivables $ 574 $ 478 $ 10 $ 1,062 $ — $ 1,062 Investments 105 26 — 131 — 131 Real estate (4) — 314 — 314 21 335 Equity investments in renewable energy projects — — — — 519 519 Total $ 679 $ 818 $ 10 $ 1,507 $ 540 $ 2,047 % of Debt and real estate portfolio 45 % 54 % 1 % 100 % N/A N/A Average remaining balance (5) $ 12 $ 9 $ 5 $ 10 $ 20 $ 12 (1) Transactions where the ultimate obligor is the U.S. federal government or state or local governments where the obligors are rated investment grade (either by an independent rating agency or based upon our internal credit analysis). This amount includes $474 million of U.S. federal government transactions and $205 million of transactions where the ultimate obligors are state or local governments. Transactions may have guaranties of energy savings from third party service providers, which typically are entities rated investment grade by an independent rating agency. (2) Transactions where the projects or the ultimate obligors are commercial entities that have been rated investment grade (either by an independent rating agency or based on our internal credit analysis). Of this total, $10 million of the transactions have been rated investment grade by an independent rating agency. Commercial investment grade financing receivables include $310 million of internally rated residential solar loans made on a non-recourse (3) Transactions where the projects or the ultimate obligors are commercial entities that have ratings below investment grade (either by an independent rating agency or using our internal credit analysis). (4) Includes the real estate and the lease intangible assets (including those held through equity method investments) from which we receive scheduled lease payments, typically under long-term triple net lease agreements. (5) Excludes approximately 130 transactions each with outstanding balances that are less than $1 million and that in the aggregate total $51 million.
Summary of Anticipated Maturity Dates of Financing Receivables and Investments and Weighted Average Yield	The following table provides a summary of our anticipated maturity dates of our financing receivables and investments and the weighted average yield for each range of maturities as of September 30, 2017: Total Less than 1 1-5 years 5-10 years More than 10 (dollars in millions) Financing Receivables Maturities by period $ 1,062 $ 4 $ 23 $ 77 $ 958 Weighted average yield by period 5.2 % 8.7 % 5.2 % 4.9 % 5.2 % Investments Maturities by period $ 131 $ — $ 66 $ 1 $ 64 Weighted average yield by period 3.9 % — % 3.6 % 4.7 % 4.3 %
Components of Real Estate Portfolio	The components of our real estate portfolio as of September 30, 2017 and December 31, 2016, were as follows: September 30, December 31, (dollars in millions) Real Estate Land $ 226 $ 145 Lease intangibles 92 29 Accumulated amortization of lease intangibles (4 ) (2 ) Real Estate $ 314 $ 172
Schedule of Future Amortization Expenses Related to Intangible Assets and Future Minimum Rental Income Payments under Land Lease Agreements	As of September 30, 2017, the future amortization expense of these intangible assets and the future minimum rental income payments under our land lease agreements are as follows: Years Ending December 31, Future Minimum (dollars in millions) From October 1, 2017 to December 31, 2017 $ 1 $ 4 2018 3 18 2019 3 18 2020 3 18 2021 3 18 2022 3 19 Thereafter 72 674 Total $ 88 $ 769
Summary of Outstanding Deferred Funding Obligations to be Paid	The next five years of outstanding deferred funding obligations to be paid are as follows: (dollars in millions) October 1, 2017 to December 31, 2017 $ 29 2018 80 2019 69 2020 36 2021 12 Total Deferred funding obligations $ 226

Equity Method Investments (Tabl

Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Schedule of Equity Method Investments	The following is a summary of the consolidated financial position and results of operations of the significant entities accounted for using the equity method. As of As of (dollars in millions, unaudited) Current assets $ 4 $ 3 Total assets $ 115 $ 99 Current liabilities $ 5 $ 4 Total liabilities $ 37 $ 39 Members’ equity $ 78 $ 60 For the six months 2017 2016 (dollars in millions, unaudited) Revenue $ 7 $ 6 Income from continuing operations $ 3 $ 1 Net income $ 3 $ 1
Renewable Energy Projects [Member]
Schedule of Equity Method Investments	As of September 30, 2017, we held the following equity method investments: Acquisition Date Transaction Investment Partner (dollars in millions) Various Vento I, LLC $ 121 EDP Renewables June 2017 Northern Frontier, LLC 87 Various December 2015 Buckeye Wind Energy Class B Holdings, LLC 67 Invenergy February 2017 Strong Upwind Holdings IV, LLC 56 JPMorgan October 2016 Invenergy Gunsight Mountain Holdings, LLC 36 Invenergy June 2016 MM Solar Holdings, LLC 29 AES Various Other transactions 144 Various Total Equity Method Investments $ 540

Credit Facilities (Tables)

Credit Facilities (Tables)	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Schedule of Additional Detail on Credit Facility	The following table provides additional detail on our credit facility as of September 30, 2017 and December 31, 2016: September 30, December 31, (dollars in millions) Outstanding balance $ 133 $ 283 Value of collateral pledged to credit facility $ 272 $ 471 Weighted average short-term borrowing rate 3.0 % 2.3 %

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Schedule of Outstanding Non-Recourse Asset-Backed Debt and Bank Loans	We have outstanding the following asset-backed non-recourse Outstanding Balance Value of Assets Pledged September 30, December 31, Interest Maturity Date Anticipated September 30, December 31, Description of Assets Pledged HASI Sustainable Yield Bond 2013-1 $ 68 $ 75 2.79 % December 2019 $ 57 $ 87 $ 93 Financing receivables ABS Loan Agreement $ 79 $ 90 5.74 % September 2021 $ 17 $ 80 $ 97 Equity interest in Strong Upwind Holdings I, LLC HASI Sustainable Yield Bond 2015-1A $ 95 $ 97 4.28 % October 2034 $ — $ 137 $ 138 Financing receivables, real estate and real estate intangibles HASI Sustainable Yield Bond 2015-1B $ 14 $ — 5.41 % October 2034 $ — $ 137 $ — Class B Bond of HASI Sustainable Yield Bond 2015-1 HASI SYB Loan Agreement 2015-1 $ — (1) $ 74 $ — (1) (1) $ — (1) $ — (1) $ 96 Equity interest in Strong Upwind Holdings II and III, LLC, related interest rate swap 2017 Credit Agreement $ 198 $ — 3.55 % (2) June 2024 $ — $ 243 $ — Equity interests in Strong Upwind Holdings I, II, III, and IV LLC, and Northern Frontier, LLC HASI SYB Loan Agreement 2015-2 $ 37 $ 41 5.41 % (3) December 2023 $ — $ 67 $ 70 Equity interest in Buckeye Wind Energy Class B Holdings LLC, related interest rate swap HASI SYB Loan Agreement 2015-3 $ 146 $ 150 4.92 % December 2020 $ 127 $ 172 $ 175 Residential solar financing receivables, related interest rate swaps HASI SYB Loan Agreement 2016-1 $ 118 $ 98 4.37 % (3) November 2021 $ 101 $ 138 $ 114 Residential solar financing receivables, related interest rate swaps HASI SYB Trust 2016-2 $ 86 $ — 4.35 % April 2037 $ — $ 88 $ — Financing receivables 2017 Master Repurchase Agreement $ 37 $ — 3.96 % (3) July 2019 $ 31 $ 41 $ — Financing receivables and investments HASI ECON 101 Trust $ 134 $ — 3.57 % May 2041 $ — $ 139 $ — Financing receivables and investments Other non-recourse debt (4) $ 85 $ 84 2.26% - 2017 to 2046 $ — $ 224 $ 81 Financing receivables Debt issuance costs (5) $ (21 ) $ (17 ) Non-recourse (6) $ 1,076 $ 692 (1) This non-recourse re-financed (2) Interest rate represents the current period’s LIBOR based rate plus the spread. Under the terms of the 2017 Credit Agreement, this rate will become fixed upon the lender’s syndication of the loan, or the rate can be fixed at our option. (3) Interest rate represents the current period’s LIBOR based rate plus the spread. Also see the interest rate swap contracts shown in the table below, the value of which are not included in the book value of assets pledged or the interest rate of the debt instrument. (4) Other non-recourse (5) Excludes costs of approximately $2 million associated with the 2017 Master Repurchase Agreement that were recorded in other assets due to the nature of the costs. (6) The total collateral pledged against our non-recourse
Schedule of Interest Rate Swaps which are Designated as Cash Flow Hedges	In connection with several of our non-recourse Notional Value as of Fair Value as of Base Rate Hedged September 30, December 31, September 30, December 31, Term HASI SYB Loan Agreement 2015-1 (1) 3 month Libor 1.55 % $ — $ 67 $ — $ — December 2015 to September 2021 HASI SYB Loan Agreement 2015-2 3 month Libor 1.52 % $ 36 $ 37 $ — $ — December 2015 to December 2018 HASI SYB Loan Agreement 2015-2 3 month Libor 2.55 % $ 29 $ 29 $ (0.3 ) $ (0.2 ) December 2018 to December 2024 HASI SYB Loan Agreement 2015-3 1 month Libor 2.34 % $ 119 $ 119 $ (0.1 ) $ 1.0 November 2020 to August 2028 HASI SYB Loan Agreement 2016-1 3 month Libor 1.88 % $ 119 $ 72 $ 0.1 $ 0.2 November 2016 to November 2021 HASI SYB Loan Agreement 2016-1 3 month Libor 2.73 % $ 107 $ 107 $ (1.0 ) $ — November 2021 to October 2032 Total $ 410 $ 431 $ (1.3 ) $ 1.0 (1) This interest rate swap was financially settled in June 2017.
Summary of Analysis of Financial Statement Line Item Impacted by Cash Flow Hedges in Condensed Consolidated Statement of Operations	The following is an analysis of the financial statement line item impacted by our cash flow hedges in our condensed consolidated statement of operations: Three months ended Nine months ended (dollars in thousands) 2017 2016 2017 2016 Total interest expense $ 17,584 $ 10,635 $ 46,728 $ 32,945 Impact of hedging $ 201 $ 253 $ 798 $ 1,042
Schedule of Minimum Maturities of Non-Recourse Debt	Our future stated minimum maturities of non-recourse (dollars in millions) October 1, 2017 to December 31, 2017 $ 24 2018 51 2019 142 2020 178 2021 146 2022 21 Thereafter 535 $ 1,097 Deferred financing costs, net (21 ) Total non-recourse $ 1,076
4.125% Convertible Senior Notes Due September 1, 2022 [Member]
Summary of Components of Convertible Notes	The following table presents a summary of the components of the Convertible Notes (dollars in millions): September 30, Principal $ 150 Accrued interest 1 Less: Unamortized financing costs (5 ) Carrying value of Convertible Notes $ 146

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Summary of Dividends Declared by Board of Directors	Our board of directors declared the following dividends in 2016 and 2017: Announced Date Record Date Pay Date Amount per 3/15/16 3/30/16 4/7/16 $ 0.30 6/07/16 7/06/16 7/14/16 $ 0.30 9/15/16 10/05/16 10/13/16 $ 0.30 12/13/16 12/29/16 (1) 1/12/17 $ 0.33 3/15/17 4/05/17 4/13/17 $ 0.33 6/01/17 7/06/17 7/13/17 $ 0.33 9/12/17 10/05/17 10/16/17 $ 0.33 (1) This dividend was treated as a distribution in 2017 for tax purposes.
Schedule of Common Stock Public Offerings and ATM	We completed the following public offerings and ATM offerings of our common stock in 2016 and 2017: Closing Date Common Stock Shares Issued (1) Price Net (2) (amounts in millions, except per share amounts) 6/21/16 Public Offering 4.600 $ 19.78 (3) $ 91 5/9/16 to 6/30/16 ATM 0.065 $ 20.31 (4) $ 1 11/09/16 Public Offering 4.025 $ 19.28 (3) $ 77 12/13/16 to 12/29/16 ATM 0.407 $ 19.47 (4) $ 8 1/20/17 to 2/2/17 ATM 0.197 $ 19.18 (4) $ 4 3/10/17 Public Offering 3.450 $ 18.73 (3) $ 64 5/17/17 to 6/22/17 ATM 1.376 $ 22.71 (4) $ 31 (1) Includes shares issued in connection with the exercise of the underwriters’ option to purchase additional shares. (2) Net proceeds from the offerings is shown after deducting underwriting discounts, commissions and other offering costs. (3) Represents the price per share at which the underwriters in our public offerings purchased our shares. (4) Represents the average price per share at which investors in our ATM offerings purchased our shares.
Summary of Unvested Shares of Restricted Common Stock	A summary of the unvested shares of restricted common stock that have been issued is as follows: Restricted Weighted Average Value Ending Balance — December 31, 2015 1,248,069 $ 15.16 $ 18.9 Granted 661,055 18.62 12.3 Vested (716,264 ) 14.03 (10.0 ) Forfeited (11,188 ) 17.25 (0.2 ) Ending Balance — December 31, 2016 1,181,672 $ 17.76 $ 21.0 Granted 451,614 19.04 8.6 Vested (217,833 ) 14.15 (3.1 ) Forfeited (4,519 ) 18.72 (0.1 ) Ending Balance — September 30, 2017 1,410,934 $ 18.72 $ 26.4 A summary of the unvested shares of restricted stock units that have market based vesting conditions that have been issued is as follows: Restricted Stock (1) Weighted Average Value Ending Balance — December 31, 2016 — — — Granted 256,034 $ 18.99 $ 4.9 Vested (376 ) 18.99 — Forfeited (1,202 ) 18.99 — Ending Balance — September 30, 2017 254,456 $ 18.99 $ 4.9 (1) As discussed in Note 2 these restricted stock units vest between 0% and 200% of the target. The amounts shown represent the number of restricted stock units at 100% of target.

Earnings per Share of Common 29

Earnings per Share of Common Stock (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Earnings Per Common Share of Common Stock	The computation of basic and diluted earnings per common share of common stock is as follows: Three Months Ended Nine Months Ended Numerator: 2017 2016 2017 2016 (in millions, except share and per share data) Net income attributable to controlling stockholders and participating securities $ 7.9 $ 3.3 $ 27.5 $ 10.2 Less: Dividends paid on participating securities (0.4 ) (0.4 ) (1.5 ) (1.3 ) Undistributed earnings attributable to participating securities — — — — Net income attributable to controlling stockholders $ 7.5 $ 2.9 $ 26.0 $ 8.9 Denominator: Weighted-average number of common shares — basic 51,655,868 41,988,036 49,924,224 38,924,977 Weighted-average number of common shares — diluted 51,655,868 41,988,036 49,924,224 38,924,977 Basic earnings per common share $ 0.14 $ 0.07 $ 0.52 $ 0.23 Diluted earnings per common share $ 0.14 $ 0.07 $ 0.52 $ 0.23 Other Information: Weighted-average number of OP units 284,992 284,992 284,992 284,992 Unvested restricted common stock outstanding as of 1,410,934 1,323,460 1,410,934 1,323,460 Unvested restricted stock units outstanding as of 254,456 — 254,456 —

Summary of Significant Accoun30

Summary of Significant Accounting Policies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017Segment
Summary of Significant Accounting Policies [Line Items]
Financing receivable, past due	90 days
Cash and cash equivalents original maturity period	3 months
Real estate investment description	To qualify as a REIT, we must meet on an ongoing basis a number of organizational and operational requirements, including a requirement that we currently distribute at least 90% of our net taxable income, excluding capital gains, to our stockholders.
Number of segment reported	1
2013 Plan [Member] | Performance Based Restricted Stock Award [Member]
Summary of Significant Accounting Policies [Line Items]
Stock-based award vesting minimum percentage	0.00%
Stock-based award vesting maximum percentage	200.00%
Stock-based award, range of vesting percentage description	The award earned is generally between 0% and 200% of the initial target, depending on the extent to which the performance target is met.
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Percentage of taxable income distributed to stockholders	90.00%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value [Member] | Level 3 [Member] | Credit Facilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	$ 175	$ 283
Fair Value [Member] | Level 3 [Member] | Non-recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	1,103	718
Fair Value [Member] | Level 3 [Member] | Financing Receivable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,044	1,017
Fair Value [Member] | Level 3 [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	131	58
Fair Value [Member] | Level 3 [Member] | Securitization Residual Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	35	19
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Convertible Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	156
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	1
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		1
Carrying Value [Member] | Level 3 [Member] | Credit Facilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	175	283
Carrying Value [Member] | Level 3 [Member] | Non-recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	1,097	709
Carrying Value [Member] | Level 3 [Member] | Financing Receivable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,062	1,042
Carrying Value [Member] | Level 3 [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	131	58
Carrying Value [Member] | Level 3 [Member] | Securitization Residual Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	35	19
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Convertible Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	151
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	$ 1
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		$ 1

Fair Value Measurements - Sum32

Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Parenthetical) (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Financing receivables held for sale	$ 0	$ 0
Amortized cost	$ 131,000,000	$ 61,000,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Reconciliation of Level 3 Investments Securities (Detail) - Debt Securities [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ 126	$ 48	$ 58	$ 29
Purchases of investments	5	2	71	34
Payments on investments			(1)	(1)
Sale of investments				(14)
Realized gains on investments recorded in earnings				1
Unrealized gains (losses) on investments recorded in OCI			3	1
Balance, end of period	$ 131	$ 50	$ 131	$ 50

Fair Value Measurements - Sch34

Fair Value Measurements - Schedule of Reconciliation of Level 3 Investments Securities (Parenthetical) (Detail) $ in Millions	Sep. 30, 2017USD ($)Security	Dec. 31, 2016USD ($)Security
Fair Value Disclosures [Abstract]
Investment grade rated debt held for more than 12 months	$ 10	$ 10
Securities in unrealized loss position	$ 1	$ 1
Securities in unrealized loss position | Security	0	0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - Level 3 [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Fair value interest rate spreads, minimum	1.00%	1.00%
Fair value interest rate spreads, maximum	4.00%	4.00%

Fair Value Measurements - Sch36

Fair Value Measurements - Schedule of Cash Deposits Subject to Credit Risk (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Cash deposits	$ 90,752	$ 29,428
Restricted cash deposits (included in other assets)	68,000	30,000
Total cash deposits	159,000	59,000
Amount of cash deposits in excess of amounts federally insured	$ 157,000	$ 57,000

Non-Controlling Interest - Addi

Non-Controlling Interest - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Noncontrolling Interest [Line Items]
Exchange of operating partnership units to common stock	0	0
Payment in cash for redemption of operating partnership units	$ 0
Maximum [Member]
Noncontrolling Interest [Line Items]
Outstanding OP units held by outside limited partners	1.00%

Securitization of Receivables -

Securitization of Receivables - Summary of Certain Transactions with Securitization Trusts (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Gains on securitizations	$ 18,136	$ 8,730
Securitization Trust [Member]
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Gains on securitizations	15,000	13,000
Purchase of receivables securitized	277,000	394,000
Proceeds from securitizations	292,000	407,000
Cash received from residual and servicing assets	4,000	2,000
Securitization Trust [Member] | Residual Assets [Member]
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Residual and servicing assets included in other assets	$ 35,000	$ 18,000

Securitization of Receivables39

Securitization of Receivables - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Managed receivables	$ 4,600,000,000		$ 3,900,000,000
Securitization credit losses	0	$ 0
Asset-backed Securities, Securitized Loans and Receivables [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Managed receivables	2,500,000,000		$ 2,300,000,000
Greater than 90 Days Past Due [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Payment from debtors to securitization trust	$ 1,800,000
Minimum [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Discount rates to determine fair market value of underlying assets	4.00%
Maximum [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Annual servicing fees	0.20%
Discount rates to determine fair market value of underlying assets	7.00%

Our Portfolio - Additional Info

Our Portfolio - Additional Information (Detail)	3 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2017USD ($)aProject	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)	Jun. 30, 2017USD ($)
Financing Receivable, Recorded Investment [Line Items]
Financing receivables, investments, real estate and equity method investments		$ 2,047,000,000
Financing receivables on non accrual status		0		$ 0
Loan modifications that qualify as trouble debt restructurings		0		0
Provision for credit losses		0		0
Land purchased | a	4,000
Number of solar projects | Project	20
Portfolio cost	$ 145,000,000	142,952,000	$ 10,964,000
Deferred funding obligations		225,817,000		170,892,000
Escrow deposits		165,000,000
Investment securities pledged as collateral		29,000,000		41,000,000
Investment Contracts [Member]
Financing Receivable, Recorded Investment [Line Items]
Investment in project		10,000,000
Financing Receivables and Investments [Member]
Financing Receivable, Recorded Investment [Line Items]
Deferred funding obligations		$ 20,000,000		$ 34,000,000
American Wind Capital Company, LLC ("AWCC") [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables, carrying value that became past due					$ 10,000,000
Real Estate Portfolio [Member]
Financing Receivable, Recorded Investment [Line Items]
Real estate portfolio acquired value through equity interest in joint venture	$ 21,000,000
Joint Venture [Member]
Financing Receivable, Recorded Investment [Line Items]
Land purchased | a	1,100
Lease Intangibles [Member]
Financing Receivable, Recorded Investment [Line Items]
Portfolio cost	$ 56,000,000
Minimum [Member]
Financing Receivable, Recorded Investment [Line Items]
Long-term triple net leases expiration dates range		2,033
Long-term triple net leases extended expiration dates range		2,047
Maximum [Member]
Financing Receivable, Recorded Investment [Line Items]
Long-term triple net leases expiration dates range		2,057
Long-term triple net leases extended expiration dates range		2,080

Our Portfolio - Analysis of Por

Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	$ 1,062,000
Investments	130,540	$ 58,058
Investments	130,540	58,058
Real estate	335,000
Equity method investments	540,150	$ 363,297
Total	2,047,000
Average remaining balance	12,000
Renewable Energy Projects [Member]
Financing Receivable, Recorded Investment [Line Items]
Equity method investments	519,000
Commercial Investment Grade [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	478,000
Investments	26,000
Investments	26,000
Real estate	314,000
Total	818,000
Average remaining balance	9,000
Commercial Non-Investment Grade [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	10,000
Total	10,000
Average remaining balance	$ 5,000
Credit Concentration Risk [Member] | Commercial Investment Grade [Member] | Debt and Real Estate Portfolio [Member]
Financing Receivable, Recorded Investment [Line Items]
% of Debt and real estate portfolio	54.00%
Credit Concentration Risk [Member] | Commercial Non-Investment Grade [Member] | Debt and Real Estate Portfolio [Member]
Financing Receivable, Recorded Investment [Line Items]
% of Debt and real estate portfolio	1.00%
Government [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	$ 574,000
Investments	105,000
Investments	105,000
Total	679,000
Average remaining balance	$ 12,000
Government [Member] | Credit Concentration Risk [Member] | Debt and Real Estate Portfolio [Member]
Financing Receivable, Recorded Investment [Line Items]
% of Debt and real estate portfolio	45.00%
Subtotal, Debt and Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivables	$ 1,062,000
Investments	131,000
Investments	131,000
Real estate	314,000
Total	1,507,000
Average remaining balance	$ 10,000
Subtotal, Debt and Real Estate [Member] | Credit Concentration Risk [Member] | Debt and Real Estate Portfolio [Member]
Financing Receivable, Recorded Investment [Line Items]
% of Debt and real estate portfolio	100.00%
Equity Method Investments [Member]
Financing Receivable, Recorded Investment [Line Items]
Real estate	$ 21,000
Total	540,000
Average remaining balance	20,000
Equity Method Investments [Member] | Renewable Energy Projects [Member]
Financing Receivable, Recorded Investment [Line Items]
Equity method investments	$ 519,000

Our Portfolio - Analysis of P42

Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Parenthetical) (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)Transactions	Dec. 31, 2016USD ($)
Financing Receivable, Recorded Investment [Line Items]
Total financing receivable	$ 1,062,051	$ 1,042,237
Number of transactions | Transactions	130
Financial receivable outstanding, Average Remaining Balance	$ 12,000
Total aggregate remaining balance	51,000
Maximum [Member]
Financing Receivable, Recorded Investment [Line Items]
Financial receivable outstanding, Average Remaining Balance	1,000
Investment Grade By Independent Rating Agency [Member]
Financing Receivable, Recorded Investment [Line Items]
Total financing receivable	10,000
U.S. Federal Government [Member]
Financing Receivable, Recorded Investment [Line Items]
Total financing receivable	474,000
State, Local, Institutions [Member]
Financing Receivable, Recorded Investment [Line Items]
Total financing receivable	205,000
Commercial Investment Grade [Member]
Financing Receivable, Recorded Investment [Line Items]
Financial receivable outstanding, Average Remaining Balance	9,000
Commercial Investment Grade [Member] | Residential Solar Loan [Member] | Subsidiaries Of SunPower Corporation [Member]
Financing Receivable, Recorded Investment [Line Items]
Total financing receivable	$ 310,000

Our Portfolio - Summary of Anti

Our Portfolio - Summary of Anticipated Maturity Dates of Financing Receivables and Investments and Weighted Average Yield (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Receivables [Abstract]
Financing receivables, maturities total	$ 1,062
Financing receivables, maturities in less than 1 year	4
Financing receivables, maturities in 1-5 years	23
Financing receivables, maturities in 5-10 years	77
Financing receivables,maturities in more than 10 years	$ 958
Financing receivables, weighted average yield total	5.20%
Financing receivables, weighted average yield in less than 1 year	8.70%
Financing receivables, weighted average yield in 1-5 years	5.20%
Financing receivables, weighted average yield in 5-10 years	4.90%
Financing receivables, weighted average yield in more than 10 years	5.20%
Investments, maturities total	$ 131
Investments, maturities in less than 1 year	0
Investments, maturities in 5-10 years	66
Investments, maturities in 1-5 years	1
Investments, maturities in more than 10 years	$ 64
Investments, weighted average yield total	3.90%
Investments, weighted average yield in less than 1 year	0.00%
Investments, weighted average yield in 1-5 years	3.60%
Investments, weighted average yield in 5-10 years	4.70%
Investments, weighted average yield in more than 10 years	4.30%

Our Portfolio - Components of R

Our Portfolio - Components of Real Estate Portfolio (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Real Estate Properties [Line Items]
Accumulated amortization of lease intangibles	$ (4)	$ (2)
Real Estate	314	172
Land [Member]
Real Estate Properties [Line Items]
Real Estate	226	145
Lease Intangibles [Member]
Real Estate Properties [Line Items]
Real Estate	$ 92	$ 29

Our Portfolio - Schedule of Fut

Our Portfolio - Schedule of Future Amortization Expenses Related to Intangible Assets and Future Minimum Rental Income Payments under Land Lease Agreements (Detail) $ in Millions	Sep. 30, 2017USD ($)
Intangible Liability Disclosure [Abstract]
From October 1, 2017 to December 31, 2017	$ 1
2,018	3
2,019	3
2,020	3
2,021	3
2,022	3
Thereafter	72
Net intangible assets	88
From October 1, 2017 to December 31, 2017	4
2,018	18
2,019	18
2,020	18
2,021	18
2,022	19
Thereafter	674
Total	$ 769

Our Portfolio - Schedule of Equ

Our Portfolio - Schedule of Equity Method Investments (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Jun. 30, 2017	Feb. 28, 2017	Oct. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Projects investment amount	$ 540
Vento I, LLC [Member] | EDP Renewables [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount	121
Strong Upwind Holdings IV, LLC [Member] | JP Morgan [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount			$ 56
Northern Frontier LLC [Member] | Various [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount		$ 87
Buckeye Wind Energy Class B Holdings LLC [Member] | Invenergy [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount						$ 67
MM Solar Holdings LLC [Member] | AES [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount					$ 29
Invenergy Gunsight Mountain Holdings LLC [Member] | Invenergy [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount				$ 36
Other Transactions [Member] | Various [Member] | Renewable Energy Projects [Member]
Schedule of Equity Method Investments [Line Items]
Projects investment amount	$ 144

Our Portfolio - Summary of Outs

Our Portfolio - Summary of Outstanding Deferred Funding Obligations to be Paid (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
October 1, 2017 to December 31, 2017	$ 29,000
2,018	80,000
2,019	69,000
2,020	36,000
2,021	12,000
Total Deferred funding obligations	$ 225,817	$ 170,892

Credit Facilities - Additional

Credit Facilities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017USD ($)
Line of Credit Facility [Line Items]
Unamortized issuance costs	$ 5,000,000
Fees for loan agreement description	Fees for each loan agreement equal to 0.50%, divided by 360, multiplied by the excess of the available borrowing capacity under each component of the credit facility over the actual amount borrowed under such component.
Default underlying financings	50.00%
Qualifying Project Finance Loans (PF Facility) [Member]
Line of Credit Facility [Line Items]
London Interbank Offered Rate	LIBOR plus 2.5%
Floating interest rate	2.50%
Applicable valuation percentages	67.00%
London Interbank Offered Rate (LIBOR) [Member] | Qualifying Government and Institutional Loans (G&I Facility) [Member]
Line of Credit Facility [Line Items]
London Interbank Offered Rate	("LIBOR") plus 1.5%
Floating interest rate	1.50%
Fixed interest rate	1.50%
London Interbank Offered Rate (LIBOR) [Member] | Qualifying Government and Institutional Loans (G&I Facility) [Member] | 1.5% [Member]
Line of Credit Facility [Line Items]
Floating interest rate	1.00%
London Interbank Offered Rate (LIBOR) [Member] | Qualifying Project Finance Loans (PF Facility) [Member]
Line of Credit Facility [Line Items]
Fixed interest rate	2.50%
London Interbank Offered Rate (LIBOR) [Member] | Qualifying Project Finance Loans (PF Facility) [Member] | 1.5% [Member]
Line of Credit Facility [Line Items]
Floating interest rate	1.00%
Federal Funds Effective Swap Rate [Member] | Qualifying Government and Institutional Loans (G&I Facility) [Member] | 1.5% [Member]
Line of Credit Facility [Line Items]
Floating interest rate	0.50%
Federal Funds Effective Swap Rate [Member] | Qualifying Project Finance Loans (PF Facility) [Member]
Line of Credit Facility [Line Items]
London Interbank Offered Rate	The Federal Funds Rate plus 0.5%
Federal Funds Effective Swap Rate [Member] | Qualifying Project Finance Loans (PF Facility) [Member] | 1.5% [Member]
Line of Credit Facility [Line Items]
Floating interest rate	0.50%
Base Rate [Member] | Qualifying Project Finance Loans (PF Facility) [Member]
Line of Credit Facility [Line Items]
Floating interest rate	0.00%
Credit Default Option [Member] | Qualifying Government and Institutional Loans (G&I Facility) [Member]
Line of Credit Facility [Line Items]
London Interbank Offered Rate	LIBOR plus 2.50%
Floating interest rate	2.50%
Credit Default Option [Member] | Qualifying Project Finance Loans (PF Facility) [Member]
Line of Credit Facility [Line Items]
London Interbank Offered Rate	LIBOR plus 5.00%
Floating interest rate	5.00%
Loans Payable [Member]
Line of Credit Facility [Line Items]
Outstanding short-term loans borrowed	$ 42,000,000
Short-term loans borrowed	102,000,000
Senior Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum advances on credit facilities	1,500,000,000
Credit facility outstanding	$ 500,000,000
Maturity month and year	2019-07
U.S. Federal Government [Member] | Qualifying Government and Institutional Loans (G&I Facility) [Member]
Line of Credit Facility [Line Items]
Applicable valuation percentages	85.00%
Institutional [Member] | Qualifying Government and Institutional Loans (G&I Facility) [Member]
Line of Credit Facility [Line Items]
Applicable valuation percentages	80.00%

Credit Facilities - Schedule of

Credit Facilities - Schedule of Additional Detail on Credit Facility (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Outstanding balance	$ 174,742	$ 283,346
Senior Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding balance	133,000	283,000
Value of collateral pledged to credit facility	$ 272,000	$ 471,000
Weighted average short-term borrowing rate	3.00%	2.30%

Long-term Debt - Schedule of Ou

Long-term Debt - Schedule of Outstanding Non-Recourse Asset-Backed Debt and Bank Loans (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]
Debt issuance costs	$ (21)
Value of Assets Pledged, Equity interest	$ 29	$ 41
Minimum [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	2.26%
Non-recourse Asset-Backed Debt, Maturity Date	2017-12
Maximum [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	7.45%
Non-recourse Asset-Backed Debt, Maturity Date	2046-12
HASI Sustainable Yield Bond 2013-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	2.79%
Non-recourse Asset-Backed Debt, Maturity Date	2019-12
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 57
ABS Loan Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	5.74%
Non-recourse Asset-Backed Debt, Maturity Date	2021-09
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 17
HASI Sustainable Yield Bond 2015-1A [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.28%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
HASI Sustainable Yield Bond 2015-1B [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	5.41%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
2017 Credit Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	3.55%
Non-recourse Asset-Backed Debt, Maturity Date	2024-06
HASI SYB Loan Agreement 2015-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	5.41%
Non-recourse Asset-Backed Debt, Maturity Date	2023-12
HASI SYB Loan Agreement 2015-3 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.92%
Non-recourse Asset-Backed Debt, Maturity Date	2020-12
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 127
HASI SYB Loan Agreement 2016-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.37%
Non-recourse Asset-Backed Debt, Maturity Date	2021-11
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 101
HASI SYB Trust 2016-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.35%
Non-recourse Asset-Backed Debt, Maturity Date	2037-04
2017 Master Repurchase Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	3.96%
Non-recourse Asset-Backed Debt, Maturity Date	2019-07
Non-recourse Asset-Backed Debt, Anticipated Balance at Maturity	$ 31
HASI ECON 101 Trust [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	3.57%
Non-recourse Asset-Backed Debt, Maturity Date	2041-05
Asset-Backed Nonrecourse Debt Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Other non-recourse debt	$ 85	84
Debt issuance costs	(21)	(17)
Outstanding Balance	1,076	692
Value of Assets Pledged, Equity interest	$ 224	81
Description of Assets Pledged	Financing receivables
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2013-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 68	75
Value of Assets Pledged, Equity interest	$ 87	93
Description of Assets Pledged	Financing receivables
Asset-Backed Nonrecourse Debt Agreement [Member] | ABS Loan Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 79	90
Value of Assets Pledged, Equity interest	$ 80	97
Description of Assets Pledged	Equity interest in Strong Upwind Holdings I, LLC
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1A [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 95	97
Non-recourse Asset-Backed Debt, Interest Rate	4.28%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
Value of Assets Pledged, Equity interest	$ 137	138
Description of Assets Pledged	Financing receivables, real estate and real estate intangibles
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1B [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 14
Non-recourse Asset-Backed Debt, Interest Rate	5.00%
Non-recourse Asset-Backed Debt, Maturity Date	2034-10
Value of Assets Pledged, Equity interest	$ 137
Description of Assets Pledged	Class B Bond of HASI Sustainable Yield Bond 2015-1
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2015-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance		74
Value of Assets Pledged, Equity interest		96
Description of Assets Pledged	Equity interest in Strong Upwind Holdings II and III, LLC, related interest rate swap
Asset-Backed Nonrecourse Debt Agreement [Member] | 2017 Credit Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 198
Value of Assets Pledged, Equity interest	$ 243
Description of Assets Pledged	Equity interests in Strong Upwind Holdings I, II, III, and IV LLC, and Northern Frontier, LLC
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2015-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 37	41
Value of Assets Pledged, Equity interest	$ 67	70
Description of Assets Pledged	Equity interest in Buckeye Wind Energy Class B Holdings LLC, related interest rate swap
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2015-3 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 146	150
Value of Assets Pledged, Equity interest	$ 172	175
Description of Assets Pledged	Residential solar financing receivables, related interest rate swaps
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2016-1 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 118	98
Value of Assets Pledged, Equity interest	$ 138	$ 114
Description of Assets Pledged	Residential solar financing receivables, related interest rate swaps
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Trust 2016-2 [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 86
Value of Assets Pledged, Equity interest	$ 88
Description of Assets Pledged	Financing receivables
Asset-Backed Nonrecourse Debt Agreement [Member] | 2017 Master Repurchase Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 37
Value of Assets Pledged, Equity interest	$ 41
Description of Assets Pledged	Financing receivables and investments
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI ECON 101 Trust [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Outstanding Balance	$ 134
Value of Assets Pledged, Equity interest	$ 139
Description of Assets Pledged	Financing receivables and investments

Long-term Debt - Schedule of 51

Long-term Debt - Schedule of Outstanding Non-Recourse Asset-Backed Debt and Bank Loans (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]
Debt issuance costs	$ 21
Asset-Backed Nonrecourse Debt Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Debt issuance costs	21	$ 17
Total collateral pledged against our nonrecourse debt	1,416	$ 864
Other Assets [Member] | 2017 Master Repurchase Agreement [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Debt issuance costs	$ 2

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jan. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Non-recourse Asset-Backed Debt, Aggregate Principal Amount		$ 1,076,326,000		$ 1,076,326,000			$ 692,091,000
Total interest expense		17,584,000	$ 10,635,000	46,728,000	$ 32,945,000
SunPower Corporation [Member] | Residential Solar Loan [Member]
Debt Instrument [Line Items]
Outstanding Balance		$ 5,000,000		5,000,000
Payment of principal and interest on loan				$ 1,000,000
HASI Sustainable Yield Bond 2015-1A [Member]
Debt Instrument [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate		4.28%		4.28%
Non-recourse Asset-Backed Debt, Maturity Date				2034-10
HASI Sustainable Yield Bond 2015-1B [Member]
Debt Instrument [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate		5.41%		5.41%
Non-recourse Asset-Backed Debt, Maturity Date				2034-10
4.125% Convertible Senior Notes Due September 1, 2022 [Member]
Debt Instrument [Line Items]
Non-recourse Asset-Backed Debt, Interest Rate	4.125%
Outstanding Balance	$ 145,000,000	$ 146,000,000		$ 146,000,000
Principal	150,000,000	150,000,000		$ 150,000,000
Maturity date				Sep. 1, 2022
Conversion of debt	$ 1,000
Conversion price per share	$ 36.7101
Adjustment for dividends declared	$ 0.33
Conversion of debt equals shares	5.5
Redemption price, percentage				100.00%
Redemption description				We have a redemption option to call the Convertible Notes prior to maturity (i) on or after March 1, 2022 and (ii) at any time if such a redemption is deemed reasonably necessary to preserve our qualification as a REIT. The redemption price will be equal to the principal of the notes being redeemed, plus accrued and unpaid interest. In the event of redemption after March 1, 2022, there will be an additional make-whole premium paid to the holder of the redeemed notes unless the redemption is deemed reasonably necessary to preserve our qualification as a REIT.
Total interest expense		800,000		$ 800,000
Asset-Backed Nonrecourse Debt Agreement [Member]
Debt Instrument [Line Items]
Outstanding Balance		1,076,000,000		1,076,000,000			692,000,000
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1A [Member]
Debt Instrument [Line Items]
Non-recourse Asset-Backed Debt, Aggregate Principal Amount		$ 101,000,000		$ 101,000,000
Non-recourse Asset-Backed Debt, Interest Rate		4.28%		4.28%
Non-recourse Asset-Backed Debt, Maturity Date				2034-10
Outstanding Balance		$ 95,000,000		$ 95,000,000			$ 97,000,000
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1B [Member]
Debt Instrument [Line Items]
Non-recourse Asset-Backed Debt, Aggregate Principal Amount		$ 18,000,000		$ 18,000,000		$ 14,000,000
Non-recourse Asset-Backed Debt, Interest Rate		5.00%		5.00%
Non-recourse Asset-Backed Debt, Maturity Date				2034-10
Outstanding Balance		$ 14,000,000		$ 14,000,000

Long-term Debt - Schedule of In

Long-term Debt - Schedule of Interest Rate Swaps which are Designated as Cash Flow Hedges (Detail) - Cash Flow Hedging [Member] - Interest Rate Swap [Member] - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional Value	$ 410,000,000	$ 431,000,000
Fair Value	$ (1,300,000)	1,000,000
HASI SYB Loan Agreement 2015-1 [Member]
Derivatives, Fair Value [Line Items]
Hedged Rate	1.55%
Notional Value		67,000,000
HASI SYB Loan Agreement 2015-1 [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2015-12
HASI SYB Loan Agreement 2015-1 [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2021-09
HASI SYB Loan Agreement 2015-1 [Member] | Base Rate [Member]
Derivatives, Fair Value [Line Items]
Base Rate	3 month Libor
HASI SYB Loan Agreement 2015-2 A [Member]
Derivatives, Fair Value [Line Items]
Hedged Rate	1.52%
Notional Value	$ 36,000,000	37,000,000
HASI SYB Loan Agreement 2015-2 A [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2015-12
HASI SYB Loan Agreement 2015-2 A [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2018-12
HASI SYB Loan Agreement 2015-2 A [Member] | Base Rate [Member]
Derivatives, Fair Value [Line Items]
Base Rate	3 month Libor
HASI SYB Loan Agreement 2015-2 B [Member]
Derivatives, Fair Value [Line Items]
Hedged Rate	2.55%
Notional Value	$ 29,000,000	29,000,000
Fair Value	$ (300,000)	(200,000)
HASI SYB Loan Agreement 2015-2 B [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2018-12
HASI SYB Loan Agreement 2015-2 B [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2024-12
HASI SYB Loan Agreement 2015-2 B [Member] | Base Rate [Member]
Derivatives, Fair Value [Line Items]
Base Rate	3 month Libor
HASI SYB Loan Agreement 2015-3 [Member]
Derivatives, Fair Value [Line Items]
Hedged Rate	2.34%
Notional Value	$ 119,000,000	119,000,000
Fair Value	$ (100,000)	1,000,000
HASI SYB Loan Agreement 2015-3 [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2020-11
HASI SYB Loan Agreement 2015-3 [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2028-08
HASI SYB Loan Agreement 2015-3 [Member] | Base Rate [Member]
Derivatives, Fair Value [Line Items]
Base Rate	1 month Libor
HASI SYB Loan Agreement 2016-1 A [Member]
Derivatives, Fair Value [Line Items]
Hedged Rate	1.88%
Notional Value	$ 119,000,000	72,000,000
Fair Value	$ 100,000	200,000
HASI SYB Loan Agreement 2016-1 A [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2016-11
HASI SYB Loan Agreement 2016-1 A [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2021-11
HASI SYB Loan Agreement 2016-1 A [Member] | Base Rate [Member]
Derivatives, Fair Value [Line Items]
Base Rate	3 month Libor
HASI SYB Loan Agreement 2016-1 B [Member]
Derivatives, Fair Value [Line Items]
Hedged Rate	2.73%
Notional Value	$ 107,000,000	$ 107,000,000
Fair Value	$ (1,000,000)
HASI SYB Loan Agreement 2016-1 B [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2021-11
HASI SYB Loan Agreement 2016-1 B [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Maturity	2032-10
HASI SYB Loan Agreement 2016-1 B [Member] | Base Rate [Member]
Derivatives, Fair Value [Line Items]
Base Rate	3 month Libor

Long-term Debt - Summary of Ana

Long-term Debt - Summary of Analysis of Financial Statement Line Item Impacted by Cash Flow Hedges in Condensed Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments in Hedges, at Fair Value, Net [Abstract]
Total interest expense	$ 17,584	$ 10,635	$ 46,728	$ 32,945
Impact of hedging	$ 201	$ 253	$ 798	$ 1,042

Long-term Debt - Schedule of Mi

Long-term Debt - Schedule of Minimum Maturities of Non-recourse Debt (Detail) $ in Millions	Sep. 30, 2017USD ($)
Debt Disclosure [Abstract]
Maturity of Non-recourse debt, October 1, 2017 to December 31, 2017	$ 24
Maturity of Non-recourse debt, 2018	51
Maturity of Non-recourse debt, 2019	142
Maturity of Non-recourse debt, 2020	178
Maturity of Non-recourse debt, 2021	146
Maturity of Non-recourse debt, 2022	21
Maturity of Non-recourse debt, Thereafter	535
Total minimum maturities	1,097
Deferred financing costs, net	(21)
Total non-recourse debt	$ 1,076

Long-term Debt - Summary of Com

Long-term Debt - Summary of Components of Convertible Notes (Detail) - 4.125% Convertible Senior Notes Due September 1, 2022 [Member] - USD ($) $ in Millions	Sep. 30, 2017	Aug. 31, 2017
Debt Instrument [Line Items]
Principal	$ 150	$ 150
Accrued interest	1
Unamortized financing costs	(5)
Carrying value of Convertible Notes	$ 146	$ 145

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Holiday [Line Items]
Income tax (expense) benefit	$ 5	$ 41	$ 119	$ 123
Effective income tax rate reconciliation, at federal statutory income tax rate, Percent			35.00%
Effective income tax rate reconciliation, State and local income taxes, Percent			5.00%
Maximum [Member]
Income Tax Holiday [Line Items]
Income tax (expense) benefit	$ 100	$ 100

Equity - Summary of Dividends D

Equity - Summary of Dividends Declared by Board of Directors (Detail) - $ / shares		Oct. 16, 2017	Jul. 13, 2017	Apr. 13, 2017	Jan. 12, 2017	Oct. 13, 2016	Jul. 14, 2016	Apr. 07, 2016	Sep. 30, 2017
3/30/2016 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Mar. 15, 2016
Record Date									Mar. 30, 2016
Pay Date									Apr. 7, 2016
Amount per share								$ 0.30
07/06/16 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Jun. 7, 2016
Record Date									Jul. 6, 2016
Pay Date									Jul. 14, 2016
Amount per share							$ 0.30
10/05/16 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Sep. 15, 2016
Record Date									Oct. 5, 2016
Pay Date									Oct. 13, 2016
Amount per share						$ 0.30
12/29/16 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Dec. 13, 2016
Record Date	[1]								Dec. 29, 2016
Pay Date									Jan. 12, 2017
Amount per share					$ 0.33
4/05/2017 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Mar. 15, 2017
Record Date									Apr. 5, 2017
Pay Date									Apr. 13, 2017
Amount per share				$ 0.33
7/06/2017 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Jun. 1, 2017
Record Date									Jul. 6, 2017
Pay Date									Jul. 13, 2017
Amount per share			$ 0.33
10/05/2017 Record Date [Member]
Dividends Payable [Line Items]
Announced Date									Sep. 12, 2017
Record Date									Oct. 5, 2017
Pay Date									Oct. 16, 2017
10/05/2017 Record Date [Member] | Subsequent Event [Member]
Dividends Payable [Line Items]
Amount per share		$ 0.33
[1]	This dividend was treated as a distribution in 2017 for tax purposes.

Equity - Schedule of Common Sto

Equity - Schedule of Common Stock Public Offerings and ATM (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net proceeds from follow-on from public offering	$ 98,316	$ 91,167
6/21/2016 Closing Date [Member] | Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Jun. 21, 2016
Public offerings of common stock, Shares Issued	4,600
Public offerings of common stock, Price Per Share	$ 19.78
Net proceeds from follow-on from public offering	$ 91,000
5/09/2016 to 6/30/2016 Closing Date [Member] | At the Market Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings of common stock, Shares Issued	65
Public offerings of common stock, Price Per Share	$ 20.31
Net proceeds from follow-on from public offering	$ 1,000
5/09/2016 to 6/30/2016 Closing Date [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	May 9, 2016
5/09/2016 to 6/30/2016 Closing Date [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Jun. 30, 2016
11/09/2016 Closing Date [Member] | Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Nov. 9, 2016
Public offerings of common stock, Shares Issued	4,025
Public offerings of common stock, Price Per Share	$ 19.28
Net proceeds from follow-on from public offering	$ 77,000
12/13/16 to 12/29/16 Closing Date [Member] | At the Market Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings of common stock, Shares Issued	407
Public offerings of common stock, Price Per Share	$ 19.47
Net proceeds from follow-on from public offering	$ 8,000
12/13/16 to 12/29/16 Closing Date [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Dec. 13, 2016
12/13/16 to 12/29/16 Closing Date [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Dec. 29, 2016
1/20/17 to 2/2/17 Closing Date [Member] | At the Market Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings of common stock, Shares Issued	197
Public offerings of common stock, Price Per Share	$ 19.18
Net proceeds from follow-on from public offering	$ 4,000
1/20/17 to 2/2/17 Closing Date [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Jan. 20, 2017
1/20/17 to 2/2/17 Closing Date [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Feb. 2, 2017
3/10/2017 Closing Date [Member] | Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Mar. 10, 2017
Public offerings of common stock, Shares Issued	3,450
Public offerings of common stock, Price Per Share	$ 18.73
Net proceeds from follow-on from public offering	$ 64,000
5/17/17 to 6/22/17 Closing Date [Member] | At the Market Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings of common stock, Shares Issued	1,376
Public offerings of common stock, Price Per Share	$ 22.71
Net proceeds from follow-on from public offering	$ 31,000
5/17/17 to 6/22/17 Closing Date [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	May 17, 2017
5/17/17 to 6/22/17 Closing Date [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Public offerings and ATM offerings of common stock, Closing Date	Jun. 22, 2017

Equity - Additional Information

Equity - Additional Information (Detail) - Restricted stock and restricted stock units [Member] - 2013 Plan [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 3	$ 3	$ 8	$ 7
Unrecognized compensation expense	$ 15		$ 15
Weighted-average term in which unrecognized compensation expense is expected to be recognized			2 years
Employees and Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded			707,648
Employees and Directors [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common shares vesting years			2,017
Employees and Directors [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common shares vesting years			2,021

Equity - Summary of Unvested Sh

Equity - Summary of Unvested Shares of Restricted Common Stock (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Restricted Incentive [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Restricted Shares of Common Stock/Units	1,181,672	1,248,069
Granted, Restricted Shares of Common Stock/Units	451,614	661,055
Vested, Restricted Shares of Common Stock/Units	(217,833)	(716,264)
Forfeited, Restricted Shares of Common Stock/Units	(4,519)	(11,188)
Ending Balance, Restricted Shares of Common Stock/Units	1,410,934	1,181,672
Beginning Balance, Weighted Average Share Price	$ 17.76	$ 15.16
Granted, Weighted Average Share Price	19.04	18.62
Vested, Weighted Average Share Price	14.15	14.03
Forfeited, Weighted Average Share Price	18.72	17.25
Ending Balance, Weighted Average Share Price	$ 18.72	$ 17.76
Beginning Balance, Fair Value of Restricted Shares of Common Stock	$ 21	$ 18.9
Granted, Fair Value of Restricted Shares of Common Stock	8.6	12.3
Vested, Fair Value of Restricted Shares of Common Stock	(3.1)	(10)
Forfeited, Fair Value of Restricted Shares of Common Stock	(0.1)	(0.2)
Ending Balance, Fair Value of Restricted Shares of Common Stock	$ 26.4	$ 21
Restricted stock and restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Restricted Shares of Common Stock/Units	256,034
Vested, Restricted Shares of Common Stock/Units	(376)
Forfeited, Restricted Shares of Common Stock/Units	(1,202)
Ending Balance, Restricted Shares of Common Stock/Units	254,456
Granted, Weighted Average Share Price	$ 18.99
Vested, Weighted Average Share Price	18.99
Forfeited, Weighted Average Share Price	18.99
Ending Balance, Weighted Average Share Price	$ 18.99
Granted, Fair Value of Restricted Shares of Common Stock	$ 4.9
Ending Balance, Fair Value of Restricted Shares of Common Stock	$ 4.9

Equity - Summary of Unvested 62

Equity - Summary of Unvested Shares of Restricted Common Stock (Parenthetical) (Detail) - Restricted stock and restricted stock units [Member] - 2013 Plan [Member]	9 Months Ended
	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based award vesting minimum percentage	0.00%
Stock-based award vesting maximum percentage	200.00%
Number of units vested percentage	100.00%

Earnings per Share of Common 63

Earnings per Share of Common Stock -Schedule of Computation of Basic and Diluted Earnings Per Common Share of Common Stock (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator:
Net income attributable to controlling stockholders and participating securities	$ 7,933	$ 3,329	$ 27,472	$ 10,244
Less: Dividends paid on participating securities	(400)	(400)	(1,500)	(1,300)
Undistributed earnings attributable to participating securities	0	0	0	0
Net income attributable to controlling stockholders	$ 7,500	$ 2,900	$ 26,000	$ 8,900
Denominator:
Weighted-average number of common shares - basic	51,655,868	41,988,036	49,924,224	38,924,977
Weighted-average number of common shares - diluted	51,655,868	41,988,036	49,924,224	38,924,977
Basic earnings per common share	$ 0.14	$ 0.07	$ 0.52	$ 0.23
Diluted earnings per common share	$ 0.14	$ 0.07	$ 0.52	$ 0.23
Other Information:
Weighted-average number of OP units	284,992	284,992	284,992	284,992
Unvested restricted common stock outstanding as of	1,410,934	1,323,460	1,410,934	1,323,460
Unvested restricted stock units outstanding as of	254,456		254,456

Equity Method Investments - Add

Equity Method Investments - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Income (loss) from equity method investments	$ 6,876	$ 1,331	$ 19,424	$ 2,677

Equity Method Investments - Sum

Equity Method Investments - Summary of Consolidated Financial Position and Results of Operations of Significant Entities, Accounted for Using Equity Method (Detail) - Strong Upwind Holdings LLC [Member] - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Current assets	$ 4		$ 3
Total assets	115		99
Current liabilities	5		4
Total liabilities	37		39
Members' equity	78		$ 60
Revenue	7	$ 6
Income from continuing operations	3	1
Net income	$ 3	$ 1