(14)	Commitments and Contingencies

Litigation

We are the subject of, or party to, a number of pending or threatened legal actions and claims arising in the ordinary course of our business. While many of these matters involve inherent uncertainty, we believe that the amount of the liability, if any, ultimately incurred with respect to proceedings or claims will not have a material adverse effect on our consolidated financial position as a whole or on our liquidity, capital resources or future annual results of operations. We will continue to evaluate our litigation on a quarterly basis and will establish and adjust any litigation reserves as appropriate to reflect our assessment of the then current status of litigation.

Lease Commitments

We lease certain office space, office equipment, production facilities, compressors and transportation equipment under cancelable and non-cancelable leases. Rent expense under operating leases (including renewable monthly leases) totaled $15.9 million in 2015 compared to $13.3 million in 2014 and $13.1 million in 2013. Commitments related to these lease payments are not recorded in the accompanying consolidated balance sheets. Future minimum rental commitments under non-cancelable leases having remaining lease terms in excess of one year are as follows (in thousands):

	Operating Lease Obligations
2016	$	11,819
2017		10,014
2018		8,902
2019		7,264
2020		7,238
Thereafter		29,258
	$	74,495

Transportation and Gathering Contracts

We have entered into firm transportation and gathering contracts with various pipeline carriers for the future transportation and gathering of natural gas, NGLs and oil production primarily from our properties in Pennsylvania. Under these contracts, we are obligated to transport or gather minimum daily natural gas volumes, or pay for any deficiencies at a specified reservation fee rate. In most cases, our production committed to these pipelines is expected to exceed the minimum daily volumes provided in the contracts. As of December 31, 2015, future minimum transportation and gathering fees under our commitments are as follows (in thousands):

	Transportation and Gathering Contracts ^(a)
2016	$	407,046
2017		401,517
2018		366,914
2019		366,562
2020		359,595
Thereafter		1,748,559
	$	3,650,193

^(a) The amounts in this table represent the gross amounts that we are committed to pay; however, we will record in our financial statements our proportionate share of costs based on our working interest which can vary based on volumes produced.

In addition to the amounts included in the above table, we have entered into additional agreements which are contingent on certain pipeline and gathering line modifications and/or construction. These agreements range between six and twenty year terms and are expected to begin in 2016 and 2017. Based on these contracts, we will have additional transportation obligations for natural gas volumes of 2.0 bcf per day until 2026, declining to 1.3 bcf per day through 2032 and 400,000 mcf per day until 2037. We also have gathering obligations which begin in 2017 of up to 400,000 mcf per day through 2032. Beginning in 2016, we also have transportation obligations for ethane volumes of 20,000 bbls per day and propane volumes of 20,000 bbls per day through the end of 2031.

Delivery Commitments

We have various volume delivery commitments that are primarily related to our Marcellus Shale and Oklahoma and Texas areas. We expect to be able to fulfill our contractual obligations from our own production; however, we may purchase third party volumes to satisfy our commitments or pay demand fees for commitment shortfalls, should they occur. As of December 31, 2015, our delivery commitments through 2028 were as follows:

Year Ending December 31,	Natural Gas (mmbtu per day)		Ethane and Propane (bbls per day)
2016		405,126	40,000
2017		241,301	40,000
2018		—	40,000
2019		—	20,000
2020		—	20,000
2021		—	20,000
2022¾2028		—	15,000

In addition to the amounts included in the above table, we have contracted with several pipeline companies through 2033 to deliver ethane production volumes from our Marcellus Shale wells. These agreements and related fees, which are contingent upon pipeline construction and/or modification, are for 20,000 bbls per day starting in 2016, increasing to 30,000 bbls per day in 2018 and 45,000 bbls per day in 2020 through the end of the term. In addition, we have agreements in place to deliver natural gas volumes from our Marcellus Shale wells, which are also contingent upon pipeline construction and/or modification, for 50,000 mcf per day starting in late 2017, increasing to 200,000 mcf per day in early 2019 and 300,000 mcf per day in late 2019.

Other

We also have lease acreage that is generally subject to lease expiration if initial wells are not drilled within a specified period, generally between three to five years. We do not expect to lose significant lease acreage because of failure to drill due to inadequate capital, equipment or personnel. However, based on our evaluation of prospective economics, we have allowed acreage to expire and will allow additional acreage to expire in the future. To date, our expenditures to comply with environmental or safety regulations have not been a significant component of our cost structure and are not expected to be significant in the future. However, new regulations, enforcement policies, claims for damages or other events could result in significant future costs.