Commitments and Contingencies (Tables)
 12 Months Ended
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]  
Schedule of Future Minimum Rental Payments for Operating Leases
The following is a schedule of the Company’s future minimum payments with commitments that have initial or remaining non-cancelable contractual terms in excess of one year as of December 31, 2018:
(in thousands)
 
2019
 
2020
 
2021
 
2022
 
2023
 
Thereafter
 
Total
Drilling rig commitments
 
$
43,036

 
$
4,124

 
$
—

 
$
—

 
$
—

 
$
—

 
$
47,160

Office leases
 
3,057

 
2,830

 
2,761

 
404

 
—

 
—

 
9,052

Water disposal agreements
 
2,509

 
2,516

 
2,509

 
784

 
685

 
2,946

 
11,949

Purchase obligations
 
21,600

 
17,200

 
4,900

 
—

 
—

 
—

 
43,700

Transportation agreements
 
13,020

 
13,393

 
9,061

 
1,773

 
—

 
—

 
37,247

Total
 
$
83,222

 
$
40,063

 
$
19,231

 
$
2,961

 
$
685

 
$
2,946

 
$
149,108
Oil and Gas Delivery Commitments and Contracts Disclosure [Table Text Block]
The following table summarizes the natural gas volumes the Company is required to deliver by period under these agreements:
Period
 
Total Volume Commitments (MMBtu) (1)
 
Daily Volume Commitments (MMBtu/d) (1)
January 2019 - December 2019
 
116,800,000

 
320,000

January 2020 - December 2020
 
194,800,000

 
533,600

January 2021 - December 2021
 
158,100,000

 
433,200

January 2022 - October 2022
 
19,700,000

 
64,800

Total
 
489,400,000

 
 
 
(1)
The amounts reflected within this table are the total gross volumes the Company is required to deliver per the agreements. These volumetric quantities are therefore not comparable to the Company’s net production presented in Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operation as the amounts therein are reflected net of all royalties, overriding royalties and production due to others.