SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	ITC Holdings consolidates its majority owned subsidiaries. We eliminate all intercompany balances and transactions.
Use of Estimates	The preparation of the consolidated financial statements in accordance with GAAP requires us to use estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from our estimates.
Regulation	Our Regulated Operating Subsidiaries are subject to the regulatory jurisdiction of the FERC, which issues orders pertaining to rates, recovery of certain costs, including the costs of transmission assets and regulatory assets, conditions of service, accounting, financing authorization and operating-related matters. The utility operations of our Regulated Operating Subsidiaries meet the accounting standards set forth by the Financial Accounting Standards Board (“FASB”) for the accounting effects of certain types of regulation. These accounting standards recognize the cost based rate setting process, which results in differences in the application of GAAP between regulated and non-regulated businesses. These standards require the recording of regulatory assets and liabilities for certain transactions that would have been recorded as revenue and expense in non-regulated businesses. Regulatory assets represent costs that will be included as a component of future tariff rates and regulatory liabilities represent amounts provided in the current tariff rates that are intended to recover costs expected to be incurred in the future or amounts to be refunded to customers.
Cash and Cash Equivalents	We consider all unrestricted highly-liquid temporary investments with an original maturity of three months or less at the date of purchase to be cash equivalents.
Excess Tax Benefits From Share-based Compensation	Excess tax benefits are recognized as an addition to common stock pursuant to the share-based compensation accounting standards. Cash retained as a result of those excess tax benefits are presented in the statement of cash flows as cash inflows from financing activities and cash outflows from operating activities.
Accounts Receivables	We recognize losses for uncollectible accounts based on specific identification of any such items. As of December 31, 2015 and 2014, we did not have an accounts receivable reserve.
Inventories	Materials and supplies inventories are valued at average cost. Additionally, the costs of warehousing activities are recorded here and included in the cost of materials when requisitioned.
Property, Plant and Equipment	Depreciation and amortization expense on property, plant and equipment was $135.5 million, $118.9 million and $109.4 million for 2015, 2014 and 2013, respectively. Property, plant and equipment in service at our Regulated Operating Subsidiaries is stated at its original cost when first devoted to utility service. The gross book value of assets retired less salvage proceeds is charged to accumulated depreciation. The provision for depreciation of transmission assets is a significant component of our Regulated Operating Subsidiaries’ cost of service under FERC-approved rates. Depreciation is computed over the estimated useful lives of the assets using the straight-line method for financial reporting purposes and accelerated methods for income tax reporting purposes. The composite depreciation rate for our Regulated Operating Subsidiaries included in our consolidated statements of operations was 2.1%, 2.1% and 2.2% for 2015, 2014 and 2013, respectively. The composite depreciation rates include depreciation primarily on transmission station equipment, towers, poles and overhead and underground lines that have a useful life ranging from 48 to 60 years. The portion of depreciation expense related to asset removal costs is added to regulatory liabilities or deducted from regulatory assets and removal costs incurred are deducted from regulatory liabilities or added to regulatory assets. Our Regulated Operating Subsidiaries capitalize to property, plant and equipment an allowance for the cost of equity and borrowings used during construction (“AFUDC”) in accordance with FERC regulations. AFUDC represents the composite cost incurred to fund the construction of assets, including interest expense and a return on equity capital devoted to construction of assets. The AFUDC debt of $6.8 million, $5.1 million and $8.0 million was a reduction to interest expense for 2015, 2014 and 2013, respectively. Certain projects at ITC Great Plains have been granted an incentive to include construction work in progress balances in rate base and we do not record AFUDC on those projects. For acquisitions of property, plant and equipment greater than the net book value (other than asset acquisitions accounted for under the purchase method of accounting that result in goodwill), the acquisition premium is recorded to property, plant and equipment and amortized over the estimated remaining useful lives of the assets using the straight-line method for financial reporting purposes and accelerated methods for income tax reporting purposes. Property, plant and equipment includes capital equipment inventory stated at original cost consisting of items that are expected to be used exclusively for capital projects. Property, plant and equipment at ITC Holdings and non-regulated subsidiaries is stated at its acquired cost. Proceeds from salvage less the net book value of the disposed assets is recognized as a gain or loss on disposal. Depreciation is computed based on the acquired cost less expected residual value and is recognized over the estimated useful lives of the assets on a straight-line method for financial reporting purposes and accelerated methods for income tax reporting purposes.
General Interconnection Projects	Certain capital investment at our Regulated Operating Subsidiaries relates to investments made under generator interconnection agreements. The generator interconnection agreements typically consist of both transmission network upgrades, which are a category of upgrades deemed by FERC to benefit the transmission system as a whole, as well as direct connection facilities, which are necessary to interconnect the generating facility to the transmission system and primarily benefit the generating facility. Our investments in transmission facilities are recorded to property, plant and equipment, and are recorded net of any contribution in aid of construction. Contributions in aid of construction of $17.4 million, $19.7 million and $2.6 million were recorded as reductions to property, plant and equipment during the years ended December 31, 2015, 2014 or 2013, respectively, and are included as reductions of expenditures for property, plant and equipment in our consolidated statements of cash flows when received. We also receive refundable deposits from the generator for certain investment in network upgrade facilities in advance of construction, which are recorded to current or non-current liabilities depending on the expected refund date.
Available-For-Sale Securities	We have certain investments in debt and equity securities that are classified as available-for-sale securities. These investments currently fund our two supplemental nonqualified, noncontributory, retirement benefit plans for selected management employees as described in Note 11. Unrealized gains recorded for the investments are recognized, net of tax, in the accumulated other comprehensive income component of equity. Any unrealized losses (where cost exceeds fair market value) on the investments will also be recorded in the accumulated other comprehensive income component of equity, unless the unrealized loss is other than temporary, in which case it would be recorded as an investment loss in the consolidated statements of operations.
Impairment of Long-Lived Assets	Other than goodwill, our long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If the carrying amount of the asset exceeds the expected undiscounted future cash flows generated by the asset, the asset is written down to its estimated fair value and an impairment loss is recognized in our consolidated statements of operations.
Goodwill and Intangible Assets	Under the FASB standards, goodwill is not subject to amortization. However, goodwill is subject to fair value-based rules for measuring impairment, and a resulting write-down, if any, is to be reflected in operating expense. We have goodwill recorded relating to our acquisitions of ITCTransmission and METC and ITC Midwest’s acquisition of the IP&L transmission assets. These accounting standards require that goodwill be reviewed at the reporting unit level at least annually for impairment and whenever facts or circumstances indicate that the value of goodwill may be impaired. In order to perform these impairment tests, we compare the fair value of our reporting units with their respective carrying value. Our reporting units are ITCTransmission, METC and ITC Midwest as each of them represents an individual operating segment. We determine fair value using valuation techniques based on discounted future cash flows under various scenarios as well as consider estimates of market-based valuation multiples for companies within the peer group of our reporting units. We completed our annual goodwill impairment test for our reporting units as of October 1, 2015 and determined that no impairment exists. There were no events subsequent to October 1, 2015 that indicated impairment of our goodwill. Our intangible assets have finite lives and are amortized over their useful lives. Refer to Note 6 for additional discussion on our goodwill and intangible assets.
Deferred Financing Fees and Discount or Premium on Debt	The costs related to the issuance of long-term debt are recorded to deferred financing fees and amortized over the life of the debt issue. The debt discount or premium related to the issuance of long-term debt is recorded to long-term debt and amortized over the life of the debt issue. We recorded $4.2 million, $4.1 million and $4.1 million to interest expense for the amortization of deferred financing fees and debt discounts during the years ended December 31, 2015, 2014 and 2013, respectively.
Asset Retirement Obligations	We comply with the standards set forth by the FASB for asset retirement obligations. As defined in the standards, a conditional asset retirement obligation is a legal obligation to perform an asset retirement activity in which the timing and/or method of settlement are conditional on a future event that may or may not be within our control. We have identified conditional asset retirement obligations primarily associated with the removal of equipment containing polychlorinated biphenyls (“PCBs”) and asbestos. We record a liability at fair value for a legal asset retirement obligation in the period in which it is incurred. When a new legal obligation is recorded, we capitalize the costs of the liability by increasing the carrying amount of the related long-lived asset. We accrete the liability to its present value each period and depreciate the capitalized cost over the useful life of the related asset. At the end of the asset’s useful life, we settle the obligation for its recorded amount. The standards for asset retirement obligations applied to our Regulated Operating Subsidiaries require us to recognize regulatory assets for the timing differences between the incurred costs to settle our legal asset retirement obligations and the recognition of such obligations under the standards set forth by the FASB. There were no significant changes to our asset retirement obligations in 2015. Our asset retirement obligations as of December 31, 2015 and 2014 of $5.4 million and $5.9 million, respectively, are included in other liabilities.
Financial Instruments	We comply with the standards set forth by the FASB for derivatives and hedging in accounting for financial instruments. For derivative instruments that have been designated and qualify as hedges of the exposure to variability in expected future cash flows, the gain or loss on the derivative is initially reported as a component of other comprehensive income (loss) and reclassified to the consolidated statement of operations when the underlying hedged transaction affects net income. Any hedge ineffectiveness is recognized in net income immediately at the time the gain or loss on the derivative instruments is calculated. Refer to Note 8 for additional discussion regarding derivative instruments.
Contingent Obligations	We are subject to a number of federal and state laws and regulations, as well as other factors and conditions that potentially subject us to environmental, litigation and other risks. We periodically evaluate our exposure to such risks and record liabilities for those matters when a loss is considered probable and reasonably estimable in accordance with GAAP. Our liabilities exclude any estimates for legal costs not yet incurred associated with handling these matters. The adequacy of liabilities can be significantly affected by external events or conditions that can be unpredictable; thus, the ultimate outcome of such matters could materially affect our consolidated financial statements.
Revenues	Revenues from the transmission of electricity are recognized as services are provided based on FERC-approved cost-based formula rate templates. We record a reserve for revenue subject to refund when such refund is probable and can be reasonably estimated. This reserve is recorded as a reduction to operating revenues. The cost-based formula rate templates at our Regulated Operating Subsidiaries include a true-up mechanism, whereby they compare their actual revenue requirements to their billed revenues for each year to determine any over- or under-collection of revenue requirements and record a revenue accrual or deferral for the difference. Refer to Note 4 under “Cost-Based Formula Rates with True-Up Mechanism” for a discussion of our revenue accounting under our cost-based formula rate templates.
Share-Based Payment	We have a Second Amended and Restated 2006 Long-Term Incentive Plan (“2006 LTIP”) and a 2015 Long-Term Incentive Plan (“2015 LTIP”), pursuant to which various share-based awards are granted, including options, restricted stock and performance shares. Compensation cost is recorded over the expected vesting period for restricted stock awards that are expected to vest based on their fair value at grant date. We recognize compensation cost for performance shares that are expected to vest based on their fair value at grant date over the expected vesting period. However, the compensation cost for the portion of the performance share awards subject to an adjusted diluted earnings per share growth condition is recognized based on the probable payout (net of any estimated forfeitures), which is reassessed each reporting period and subject to change. Compensation cost is recorded for stock options that are expected to vest based on their fair value at grant date, and amortized on a straight-line basis over the requisite service period and not for each separately vesting portion of the award. For certain stock option awards, expense is recognized in the period when the service condition is met upon retirement eligibility. The grant date is the date at which our commitment to issue share-based awards to an employee or a director arises, which is generally the later of the board approval date or the date of hire or promotion of the employee. We also have an Employee Stock Purchase Plan (“ESPP”), which is a compensatory plan. Compensation cost is recorded based on the fair value of the purchase options at the grant date, which corresponds to the first day of each purchase period, and is amortized over the purchase period.
Comprehensive Income (Loss)	Comprehensive income (loss) is the change in common stockholders’ equity during a period arising from transactions and events from non-owner sources, including net income, any gain or loss recognized for the effective portion of our interest rate swaps and any unrealized gain or loss associated with our available-for-sale securities.
Income Taxes	Deferred income taxes are recognized for the expected future tax consequences of events that have been recognized in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the differences between the financial statements and the tax bases of various assets and liabilities, using the tax rates expected to be in effect for the year in which the differences are expected to reverse. The accounting standards for uncertainty in income taxes prescribe a recognition threshold and a measurement attribute for tax positions taken, or expected to be taken, in a tax return that may not be sustainable. As of December 31, 2015, we did not have any uncertain income tax positions. We file income tax returns with the Internal Revenue Service and with various state and city jurisdictions. We are no longer subject to U.S. federal tax examinations for tax years 2011 and earlier. State and city jurisdictions that remain subject to examination range from tax years 2011 to 2014. In the event we are assessed interest or penalties by any income tax jurisdictions, interest and penalties would be recorded as interest expense and other expense, respectively, in our consolidated statements of operations.

SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2015

ITC Holdings consolidates its majority owned subsidiaries. We eliminate all intercompany balances and transactions.

The preparation of the consolidated financial statements in accordance with GAAP requires us to use estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from our estimates.

Regulation

Our Regulated Operating Subsidiaries are subject to the regulatory jurisdiction of the FERC, which issues orders pertaining to rates, recovery of certain costs, including the costs of transmission assets and regulatory assets, conditions of service, accounting, financing authorization and operating-related matters. The utility operations of our Regulated Operating Subsidiaries meet the accounting standards set forth by the Financial Accounting Standards Board (“FASB”) for the accounting effects of certain types of regulation. These accounting standards recognize the cost based rate setting process, which results in differences in the application of GAAP between regulated and non-regulated businesses. These standards require the recording of regulatory assets and liabilities for certain transactions that would have been recorded as revenue and expense in non-regulated businesses. Regulatory assets represent costs that will be included as a component of future tariff rates and regulatory liabilities represent amounts provided in the current tariff rates that are intended to recover costs expected to be incurred in the future or amounts to be refunded to customers.

Cash and Cash Equivalents

We consider all unrestricted highly-liquid temporary investments with an original maturity of three months or less at the date of purchase to be cash equivalents.

Excess Tax Benefits From Share-based Compensation

Excess tax benefits are recognized as an addition to common stock pursuant to the share-based compensation accounting standards. Cash retained as a result of those excess tax benefits are presented in the statement of cash flows as cash inflows from financing activities and cash outflows from operating activities.

Accounts Receivables

We recognize losses for uncollectible accounts based on specific identification of any such items. As of December 31, 2015 and 2014, we did not have an accounts receivable reserve.

Inventories

Materials and supplies inventories are valued at average cost. Additionally, the costs of warehousing activities are recorded here and included in the cost of materials when requisitioned.

Property, Plant and Equipment

Depreciation and amortization expense on property, plant and equipment was $135.5 million, $118.9 million and $109.4 million for 2015, 2014 and 2013, respectively.

Property, plant and equipment in service at our Regulated Operating Subsidiaries is stated at its original cost when first devoted to utility service. The gross book value of assets retired less salvage proceeds is charged to accumulated depreciation. The provision for depreciation of transmission assets is a significant component of our Regulated Operating Subsidiaries’ cost of service under FERC-approved rates. Depreciation is computed over the estimated useful lives of the assets using the straight-line method for financial reporting purposes and accelerated methods for income tax reporting purposes. The composite depreciation rate for our Regulated Operating Subsidiaries included in our consolidated statements of operations was 2.1%, 2.1% and 2.2% for 2015, 2014 and 2013, respectively. The composite depreciation rates include depreciation primarily on transmission station equipment, towers, poles and overhead and underground lines that have a useful life ranging from 48 to 60 years. The portion of depreciation expense related to asset removal costs is added to regulatory liabilities or deducted from regulatory assets and removal costs incurred are deducted from regulatory liabilities or added to regulatory assets. Our Regulated Operating Subsidiaries capitalize to property, plant and equipment an allowance for the cost of equity and borrowings used during construction (“AFUDC”) in accordance with FERC regulations. AFUDC represents the composite cost incurred to fund the construction of assets, including interest expense and a return on equity capital devoted to construction of assets. The AFUDC debt of $6.8 million, $5.1 million and $8.0 million was a reduction to interest expense for 2015, 2014 and 2013, respectively. Certain projects at ITC Great Plains have been granted an incentive to include construction work in progress balances in rate base and we do not record AFUDC on those projects.

For acquisitions of property, plant and equipment greater than the net book value (other than asset acquisitions accounted for under the purchase method of accounting that result in goodwill), the acquisition premium is recorded to property, plant and equipment and amortized over the estimated remaining useful lives of the assets using the straight-line method for financial reporting purposes and accelerated methods for income tax reporting purposes.

Property, plant and equipment includes capital equipment inventory stated at original cost consisting of items that are expected to be used exclusively for capital projects.

Property, plant and equipment at ITC Holdings and non-regulated subsidiaries is stated at its acquired cost. Proceeds from salvage less the net book value of the disposed assets is recognized as a gain or loss on disposal. Depreciation is computed based on the acquired cost less expected residual value and is recognized over the estimated useful lives of the assets on a straight-line method for financial reporting purposes and accelerated methods for income tax reporting purposes.

General Interconnection Projects

Certain capital investment at our Regulated Operating Subsidiaries relates to investments made under generator interconnection agreements. The generator interconnection agreements typically consist of both transmission network upgrades, which are a category of upgrades deemed by FERC to benefit the transmission system as a whole, as well as direct connection facilities, which are necessary to interconnect the generating facility to the transmission system and primarily benefit the generating facility.

Our investments in transmission facilities are recorded to property, plant and equipment, and are recorded net of any contribution in aid of construction. Contributions in aid of construction of $17.4 million, $19.7 million and $2.6 million were recorded as reductions to property, plant and equipment during the years ended December 31, 2015, 2014 or 2013, respectively, and are included as reductions of expenditures for property, plant and equipment in our consolidated statements of cash flows when received. We also receive refundable deposits from the generator for certain investment in network upgrade facilities in advance of construction, which are recorded to current or non-current liabilities depending on the expected refund date.

Available-For-Sale Securities

We have certain investments in debt and equity securities that are classified as available-for-sale securities. These investments currently fund our two supplemental nonqualified, noncontributory, retirement benefit plans for selected management employees as described in Note 11. Unrealized gains recorded for the investments are recognized, net of tax, in the accumulated other comprehensive income component of equity. Any unrealized losses (where cost exceeds fair market value) on the investments will also be recorded in the accumulated other comprehensive income component of equity, unless the unrealized loss is other than temporary, in which case it would be recorded as an investment loss in the consolidated statements of operations.

Impairment of Long-Lived Assets

Other than goodwill, our long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If the carrying amount of the asset exceeds the expected undiscounted future cash flows generated by the asset, the asset is written down to its estimated fair value and an impairment loss is recognized in our consolidated statements of operations.

Goodwill and Intangible Assets

Under the FASB standards, goodwill is not subject to amortization. However, goodwill is subject to fair value-based rules for measuring impairment, and a resulting write-down, if any, is to be reflected in operating expense. We have goodwill recorded relating to our acquisitions of ITCTransmission and METC and ITC Midwest’s acquisition of the IP&L transmission assets. These accounting standards require that goodwill be reviewed at the reporting unit level at least annually for impairment and whenever facts or circumstances indicate that the value of goodwill may be impaired. In order to perform these impairment tests, we compare the fair value of our reporting units with their respective carrying value. Our reporting units are ITCTransmission, METC and ITC Midwest as each of them represents an individual operating segment. We determine fair value using valuation techniques based on discounted future cash flows under various scenarios as well as consider estimates of market-based valuation multiples for companies within the peer group of our reporting units.

We completed our annual goodwill impairment test for our reporting units as of October 1, 2015 and determined that no impairment exists. There were no events subsequent to October 1, 2015 that indicated impairment of our goodwill. Our intangible assets have finite lives and are amortized over their useful lives. Refer to Note 6 for additional discussion on our goodwill and intangible assets.

Deferred Financing Fees and Discount or Premium on Debt

The costs related to the issuance of long-term debt are recorded to deferred financing fees and amortized over the life of the debt issue. The debt discount or premium related to the issuance of long-term debt is recorded to long-term debt and amortized over the life of the debt issue. We recorded $4.2 million, $4.1 million and $4.1 million to interest expense for the amortization of deferred financing fees and debt discounts during the years ended December 31, 2015, 2014 and 2013, respectively.

Asset Retirement Obligations

We comply with the standards set forth by the FASB for asset retirement obligations. As defined in the standards, a conditional asset retirement obligation is a legal obligation to perform an asset retirement activity in which the timing and/or method of settlement are conditional on a future event that may or may not be within our control. We have identified conditional asset retirement obligations primarily associated with the removal of equipment containing polychlorinated biphenyls (“PCBs”) and asbestos. We record a liability at fair value for a legal asset retirement obligation in the period in which it is incurred. When a new legal obligation is recorded, we capitalize the costs of the liability by increasing the carrying amount of the related long-lived asset. We accrete the liability to its present value each period and depreciate the capitalized cost over the useful life of the related asset. At the end of the asset’s useful life, we settle the obligation for its recorded amount. The standards for asset retirement obligations applied to our Regulated Operating Subsidiaries require us to recognize regulatory assets for the timing differences between the incurred costs to settle our legal asset retirement obligations and the recognition of such obligations under the standards set forth by the FASB. There were no significant changes to our asset retirement obligations in 2015. Our asset retirement obligations as of December 31, 2015 and 2014 of $5.4 million and $5.9 million, respectively, are included in other liabilities.

Financial Instruments

We comply with the standards set forth by the FASB for derivatives and hedging in accounting for financial instruments. For derivative instruments that have been designated and qualify as hedges of the exposure to variability in expected future cash flows, the gain or loss on the derivative is initially reported as a component of other comprehensive income (loss) and reclassified to the consolidated statement of operations when the underlying hedged transaction affects net income. Any hedge ineffectiveness is recognized in net income immediately at the time the gain or loss on the derivative instruments is calculated. Refer to Note 8 for additional discussion regarding derivative instruments.

Contingent Obligations

We are subject to a number of federal and state laws and regulations, as well as other factors and conditions that potentially subject us to environmental, litigation and other risks. We periodically evaluate our exposure to such risks and record liabilities for those matters when a loss is considered probable and reasonably estimable in accordance with GAAP. Our liabilities exclude any estimates for legal costs not yet incurred associated with handling these matters. The adequacy of liabilities can be significantly affected by external events or conditions that can be unpredictable; thus, the ultimate outcome of such matters could materially affect our consolidated financial statements.

Revenues

Revenues from the transmission of electricity are recognized as services are provided based on FERC-approved cost-based formula rate templates. We record a reserve for revenue subject to refund when such refund is probable and can be reasonably estimated. This reserve is recorded as a reduction to operating revenues.

The cost-based formula rate templates at our Regulated Operating Subsidiaries include a true-up mechanism, whereby they compare their actual revenue requirements to their billed revenues for each year to determine any over- or under-collection of revenue requirements and record a revenue accrual or deferral for the difference. Refer to Note 4 under “Cost-Based Formula Rates with True-Up Mechanism” for a discussion of our revenue accounting under our cost-based formula rate templates.

Share-Based Payment

We have a Second Amended and Restated 2006 Long-Term Incentive Plan (“2006 LTIP”) and a 2015 Long-Term Incentive Plan (“2015 LTIP”), pursuant to which various share-based awards are granted, including options, restricted stock and performance shares. Compensation cost is recorded over the expected vesting period for restricted stock awards that are expected to vest based on their fair value at grant date. We recognize compensation cost for performance shares that are expected to vest based on their fair value at grant date over the expected vesting period. However, the compensation cost for the portion of the performance share awards subject to an adjusted diluted earnings per share growth condition is recognized based on the probable payout (net of any estimated forfeitures), which is reassessed each reporting period and subject to change. Compensation cost is recorded for stock options that are expected to vest based on their fair value at grant date, and amortized on a straight-line basis over the requisite service period and not for each separately vesting portion of the award. For certain stock option awards, expense is recognized in the period when the service condition is met upon retirement eligibility. The grant date is the date at which our commitment to issue share-based awards to an employee or a director arises, which is generally the later of the board approval date or the date of hire or promotion of the employee.

We also have an Employee Stock Purchase Plan (“ESPP”), which is a compensatory plan. Compensation cost is recorded based on the fair value of the purchase options at the grant date, which corresponds to the first day of each purchase period, and is amortized over the purchase period.

Comprehensive Income (Loss)

Comprehensive income (loss) is the change in common stockholders’ equity during a period arising from transactions and events from non-owner sources, including net income, any gain or loss recognized for the effective portion of our interest rate swaps and any unrealized gain or loss associated with our available-for-sale securities.

Income Taxes

Deferred income taxes are recognized for the expected future tax consequences of events that have been recognized in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the differences between the financial statements and the tax bases of various assets and liabilities, using the tax rates expected to be in effect for the year in which the differences are expected to reverse.

The accounting standards for uncertainty in income taxes prescribe a recognition threshold and a measurement attribute for tax positions taken, or expected to be taken, in a tax return that may not be sustainable. As of December 31, 2015, we did not have any uncertain income tax positions.

We file income tax returns with the Internal Revenue Service and with various state and city jurisdictions. We are no longer subject to U.S. federal tax examinations for tax years 2011 and earlier. State and city jurisdictions that remain subject to examination range from tax years 2011 to 2014. In the event we are assessed interest or penalties by any income tax jurisdictions, interest and penalties would be recorded as interest expense and other expense, respectively, in our consolidated statements of operations.