The aggregate cash payments required to be paid on or about the closing date were funded with the proceeds of $7.945 billion of term loans and $400 million of funds borrowed under our revolving credit facility together with other available funds, which included $1.825 billion borrowed from Level 3 Parent, LLC. For additional information regarding CenturyLink’s financing of the Level 3 acquisition see Note 7—Long-Term Debt and Credit Facilities.
We recognized the assets and liabilities of Level 3 based on the fair value of the acquired tangible and intangible assets and assumed liabilities of Level 3 as of November 1, 2017, the consummation date of the acquisition, with the excess aggregate consideration recorded as goodwill. The estimation of such fair values and the estimation of lives of depreciable tangible assets and amortizable intangible assets required significant judgment. We completed our final fair value determination during the fourth quarter of 2018, which differed from those reflected in our consolidated financial statements at December 31, 2017.
In connection with receiving approval from the U.S. Department of Justice to complete the Level 3 acquisition we agreed to divest certain Level 3 network assets. All of those assets were sold by December 31, 2018. The proceeds from these sales were included in the proceeds from sale of property, plant and equipment in our consolidated statements of cash flows. No gain or loss was recognized with these transactions.
As of October 31, 2018, the aggregate consideration exceeded the aggregate estimated fair value of the acquired assets and assumed liabilities by $11.2 billion, which we have recognized as goodwill. The goodwill is attributable to strategic benefits, including enhanced financial and operational scale, market diversification and leveraged combined networks that we expect to realize. None of the goodwill associated with this acquisition is deductible for income tax purposes.
The following is our assignment of the aggregate consideration:
(1) Includes accounts receivable, which had a gross contractual value of $884 million on November 1, 2017 and October 31, 2018.
(2) The weighted-average amortization period for the acquired intangible assets is approximately 12.0 years.
On the acquisition date, we assumed Level 3’s contingencies. For more information on our contingencies, see Note 19—Commitments, Contingencies and Other Items.
Table:
 | Adjusted November 1, 2017 Balance as of December 31, 2017 | Purchase Price Adjustments | Adjusted November 1, 2017 Balance as of October 31, 2018
 |  | (Dollars in millions) | 
Cash,accounts receivable and other current assets(1) | $3,317 | (26) | 3,291
Property, plant and equipment | 9,311 | 157 | 9,468
Identifiable intangible assets(2) |  |  | 
Customer relationships | 8,964 | (533) | 8,431
Other | 391 | (13) | 378
Other non current assets | 782 | 216 | 998
Current liabilities, excluding current maturities of long-term debt | (1,461) | (32) | (1,493)
Current maturities of long-term debt | (7) | — | (7)
Long-term debt | (10,888) | — | (10,888)
Deferred revenue and other liabilities | (1,629) | (114) | (1,743)
Goodwill | 10,837 | 340 | 11,177
Total estimated aggregate consideration | $19,617 | (5) | 19,612


Question: What is goodwill attributable to?
Answer: strategic benefits, enhanced financial and operational scale, market diversification, leveraged combined networks