Changes in our accrued liabilities for severance expenses and leased real estate were as follows:

Severance	Real
Estate
(Dollars in millions)
Balance at December 31, 2015 . . . . . . . . . . . . . . . . . . . . . . . . .	$ 14 80
Accrued to expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	173	4
Payments, net ......................................	(89)	(20)
Reversals and adjustments ............................	—	3
Balance at December 31, 2016 . . . . . . . . . . . . . . . . . . . . . . . . .	98	67
Accrued to expense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	42	4
Liabilities assumed in acquisition of Level 3 ..............	1	4
Payments, net ......................................	(108)	(13)
Reversals and adjustments ............................	—	2
Balance at December 31, 2017 . . . . . . . . . . . . . . . . . . . . . . . . .	$ 33	64

# (9) Employee Benefits

# Pension, Post-Retirement and Other Post-Employment Benefits

We sponsor various defined benefit pension plans (qualified and non-qualified) which, in the aggregate, cover a substantial portion of our employees including legacy CenturyLink, legacy Qwest Communications International, Inc. (“Qwest”) and legacy Embarq employees. On December 31, 2015, we merged our existing qualified pension plans, which included merging the Qwest Pension Plan and Embarq Retirement Pension Plan into the CenturyLink Retirement Plan. The CenturyLink Retirement Plan was renamed the CenturyLink Combined Pension Plan (“Combined Plan”). Pension benefits for participants of the new Combined Plan who are represented by a collective bargaining agreement are based on negotiated schedules. All other participants’ pension benefits are based on each individual participant’s years of service and compensation. We also maintain non-qualified pension plans for certain current and former highly compensated employees. We maintain post-retirement benefit plans that provide health care and life insurance benefits for certain eligible retirees. We also provide other post-employment benefits for certain eligible former employees. We use a December 31 measurement date for all our plans.

# Pension Benefits

In connection with the acquisition of Level 3 Communications, Inc. on November 1, 2017, we assumed defined benefit pension plans sponsored by various Level 3 companies for their employees. Based on a valuation analysis, we recognized a \$20 million liability on November 1, 2017 for the unfunded status of the Level 3 pension plans, reflecting projected benefit obligations of 167 million, in excess of the \$147 million fair value of plan assets.

Current funding laws require a company with a pension shortfall to fund the annual cost of benefits earned in addition to a seven-year amortization of the shortfall. Our funding policy for our Combined Plan is to make contributions with the objective of accumulating sufficient assets to pay all qualified pension benefits when due under the terms of the plan. The accounting unfunded status of our qualified pension plan was \$2.004 billion and\$2.352 billion as of December 31, 2017 and 2016, respectively.

We made a voluntary cash contribution to our qualified pension plan of \$100 million in both 2017 and 2016, and paid \$5 million and \$7 million of benefits directly to participants of our non-qualified pension plans in 2017 and 2016, respectively. Based on current laws and circumstances, we are not required to make any contributions to our qualified pension plan in 2018, but we currently expect to make a voluntary contribution of \$100 million to the trust for our qualified pension plan in 2018. We estimate that in 2018 we will pay \$5 million of benefits directly to participants of our non-qualified pension plans.