The Company has also encountered various quality issues on its aircraft carrier construction and overhaul programs and its Virginia-class submarine construction program at its Newport News location.
These primarily involve matters related to filler metal used in pipe welds identified in 2007, and issues associated with non-nuclear weld inspection and the installation of weapons handling equipment on certain submarines, and certain purchased material quality issues identified in 2009.
The Company does not believe that resolution of these issues will have a material effect upon its consolidated financial position, results of operations or cash flows.
Environmental Matters—The estimated cost to complete environmental remediation has been accrued where it is probable that the Company will incur such costs in the future to address environmental conditions at currently or formerly owned or leased operating facilities, or at sites where it has been named a Potentially Responsible Party (“PRP”) by the Environmental Protection Agency, or similarly designated by another environmental agency, and these costs can be estimated by management.
These accruals do not include any litigation costs related to environmental matters, nor do they include amounts recorded as asset retirement obligations.
To assess the potential impact on the Company’s consolidated financial statements, management estimates the range of reasonably possible remediation costs that could be incurred by the Company, taking into account currently available facts on each site as well as the current state of technology and prior experience in remediating contaminated sites.
These estimates are reviewed periodically and adjusted to reflect changes in facts and technical and legal circumstances.
Management estimates that as of December 31, 2011, the probable future costs for environmental remediation is $3 million, which is accrued in other current liabilities.
Factors that could result in changes to the Company’s estimates include: modification of planned remedial actions, increases or decreases in the estimated time required to remediate, changes to the determination of legally responsible parties, discovery of more extensive contamination than anticipated, changes in laws and regulations affecting remediation requirements, and improvements in remediation technology.
Should other PRPs not pay their allocable share of remediation costs, the Company may have to incur costs exceeding those already estimated and accrued.
In addition, there are certain potential remediation sites where the costs of remediation cannot be reasonably estimated.
Although management cannot predict whether new information gained as projects progress will materially affect the estimated liability accrued, management does not believe that future remediation expenditures will have a material effect on the Company’s consolidated financial position, results of operations or cash flows.
Financial Arrangements—In the ordinary course of business, HII uses standby letters of credit issued by commercial banks and surety bonds issued by insurance companies principally to support the Company’s self-insured workers’ compensation plans.
At December 31, 2011, there were $121 million of standby letters of credit issued but undrawn and $297 million of surety bonds outstanding related to HII.
U. S.  Government Claims—From time to time, the U. S.  Government advises the Company of claims and penalties concerning certain potential disallowed costs.
When such findings are presented, the Company and U. S.  Government representatives engage in discussions to enable HII to evaluate the merits of these claims as well as to assess the amounts being claimed.
The Company does not believe that the outcome of any such matters will have a material effect on its consolidated financial position, results of operations or cash flows.
Collective Bargaining Agreements—The Company believes that it maintains good relations with its approximately 38,000 employees of which approximately 50% are covered by a total of 10 collective bargaining agreements.
The Company expects to renegotiate renewals of each of its collective bargaining agreements between 2013 and 2015 as they approach expiration.
Collective bargaining agreements generally expire after three to five years and are subject to renegotiation at that time.
It is not expected that the results of these negotiations, either individually or in the aggregate, will have a material effect on the Company’s consolidated results of operations.
Operating Leases—Rental expense for operating leases was $44 million in 2011, $44 million in 2010, and $48 million in 2009.
These amounts are net of immaterial amounts of sublease rental income.
Minimum rental commitments under longterm non-cancellable operating leases for the next five years and thereafter are:
## Table 0 ##
10.
GOODWILL AND OTHER PURCHASED INTANGIBLE ASSETS Goodwill HII performs impairment tests for goodwill as of November 30 of each year, or when evidence of potential impairment exists.
Goodwill is tested for impairment between annual impairment tests if an event occurs or circumstances change that would more likely than not reduce the fair value of the Company’s reporting units below their carrying value.
In light of the adverse equity market conditions that began in the second quarter of 2011 and the resultant decline in industry market multiples and its market capitalization, the Company performed an interim goodwill impairment analysis as of September 30, 2011.
The analysis resulted in a $290 million non-cash goodwill impairment charge recorded in the Company’s Ingalls segment in 2011.
Due to the complexities involved in determining the implied fair value of the goodwill of each reporting unit, the Company initially recorded a preliminary goodwill impairment charge of $300 million in the third quarter of 2011, which represented its best estimate of the impairment amount at the time of the filing of the Company’s third quarter report.
The goodwill impairment charge was later adjusted to $290 million in the fourth quarter of 2011, based on the final impairment analysis.
The goodwill at these businesses has no tax basis, and, accordingly, there was no tax benefit associated with recording the impairment charge.
No goodwill impairment was recognized at the Newport News segment, as the Company’s analysis indicated its fair value was in excess of its carrying value as of September 30, 2011.
The Company performed its annual goodwill impairment testing as of November 30, 2011, and determined that no further impairment was necessary, as the testing indicated the fair value of each reporting unit exceeded its corresponding carrying value.
Accumulated goodwill impairment losses at December 31, 2011 and 2010, were $2,780 million and $2,490 million, respectively.
The accumulated goodwill impairment losses at December 31, 2011 and 2010, for Ingalls were $1,568 million and $1,278 million, respectively.
The accumulated goodwill impairment losses at both December 31, 2011 and 2010, for Newport News were $1,212 million.
Prior to completing the second step related to the goodwill impairment charge in 2011, HII tested its purchased intangible assets and other long-lived assets for impairment, and the carrying values of these assets were determined not to be impaired.
The changes in the carrying amounts of goodwill during 2011 and 2010 were as follows:
## Table 1 ##
Purchased Intangible Assets The following table summarizes the Company’s aggregate purchased intangible assets, all of which are contract or program related intangible assets:
## Table 2 ##
The Company’s purchased intangible assets other than goodwill are subject to amortization on a straight-line basis over an aggregate weighted-average period of 40 years.
Remaining unamortized intangible assets consist principally of amounts pertaining to nuclear-powered aircraft carrier and submarine intangibles whose useful lives have been estimated based on the long life cycle of the related programs.
Amortization expense for the years ended December 31, 2011, 2010 and 2009, was $20 million, $23 million and $30 million, respectively.
## Table 3 ##
(a) U. S.  and international equity securities include investments in small, medium, and large capitalization stocks of public companies held in commingled trust funds.
(b) Cash and cash equivalents are liquid short-term investment funds and include net receivables and payables of the trust.
These funds are available for immediate use to fund daily operations, execute investment policies, and serve as a temporary investment vehicle.
The master trust limits the use of derivatives through direct or separate account investments, such that the derivatives used are liquid and able to be readily valued in the market.
Derivative usage in separate account structures is primarily for gaining market exposure in an unlevered manner or hedging investment risks.
The fair market value of the pension master trust's derivatives through direct or separate account investments resulted in a net asset of approximately $4 million and a net liability of $1 million as of December 31, 2018 and 2017, respectively.
There was no activity attributable to Level 3 retirement plan assets during the years ended December 31, 2018 and 2017.18.
STOCK COMPENSATION PLANS As of December 31, 2018, HII had stock-based compensation awards outstanding under the following plans: the Huntington Ingalls Industries, Inc.  2011 Long-Term Incentive Stock Plan (the "2011 Plan") and the Huntington Ingalls Industries, Inc.  2012 Long-Term Incentive Stock Plan (the "2012 Plan").
Stock Compensation Plans On March 23, 2012, the Company's board of directors adopted the 2012 Plan, subject to stockholder approval, and the Company's stockholders approved the 2012 Plan on May 2, 2012.
Award grants made on or after May 2, 2012, were made under the 2012 Plan.
Award grants made prior to May 2, 2012, were made under the 2011 Plan.
No future grants will be made under the 2011 Plan.

['

2012	$21
2013	17
2014	15
2015	13
2016	10
Thereafter	48
Total	$124

', '

($ in millions)	Ingalls	Newport News	Total
Balance as of December 31, 2009	$488	$646	$1,134
Balance as of December 31, 2010	488	646	1,134
Goodwill impairment	-290	0	-290
Balance as of December 31, 2011	$198	$646	$844

', '

December 31
($ in millions)	2011	2010
Gross carrying amount	$939	$939
Accumulated amortization	-372	-352
Net carrying amount	$567	$587

', '

December 31, 2017
($ in millions)	Total	Level 1	Level 2	Level 3
Plan assets subject to leveling
U.S. and international equities	$1,270	$1,270	$—	$—
Government and agency debt securities	409	—	409	—
Corporate and other debt securities	1,287	—	1,287	—
Group annuity contract	3	—	3	—
Cash and cash equivalents, net	—	—	—	—
Net plan assets subject to leveling	$2,969	$1,270	$1,699	$—
Plan assets not subject to leveling
U.S. and international equities (a)	2,012
Corporate and other debt securities	165
Real estate investments	279
Private partnerships	16
Hedge funds	281
Cash and cash equivalents, net (b)	115
Total plan assets not subject to leveling	2,868
Net plan assets	$5,837

']

Question: The amount of Net plan assets subject to leveling of which Level ranks first as of December 31, 2017?
Answer: 2