Royalty Interests (Details) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2018
USD ($)
a
|
Sep. 30, 2018
USD ($)
|
Jun. 30, 2018
USD ($)
|
Mar. 31, 2018
USD ($)
|
Dec. 31, 2017
USD ($)
a
|
Sep. 30, 2017
USD ($)
|
Jun. 30, 2017
USD ($)
|
Mar. 31, 2017
USD ($)
|
Dec. 31, 2018
USD ($)
a
$ / a
|
Dec. 31, 2017
USD ($)
a
|
Dec. 31, 2016
USD ($)
|
|
Net Book Value | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Royalty interests acquired | $ 24,303 | Ìý | Ìý | Ìý | $ 0 | Ìý | Ìý | Ìý | $ 24,303 | $ 0 | Ìý |
Total royalty interests | 24,303 | Ìý | Ìý | Ìý | 0 | Ìý | Ìý | Ìý | $ 24,303 | 0 | Ìý |
Royalty interests sold (in acres) | a | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 812 | Ìý | Ìý |
Royalty interest rate | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 12.50% | Ìý | Ìý |
Royalty interests sold | 93,201 | $ 73,168 | $ 73,844 | $ 60,007 | 39,957 | $ 51,977 | $ 32,293 | $ 30,407 | $ 300,220 | 154,634 | $ 66,109 |
Average price per net royalty acre sold (in dollars per acre) | $ / a | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 23,234 | Ìý | Ìý |
Acquisition of royalty interests | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 24,303 | $ 0 | 0 |
1/16th nonparticipating perpetual royalty interest | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Real Estate Properties [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Nonparticipating perpetual royalty interest rate | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 6.25% | 6.25% | Ìý |
Net Book Value | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
1/16th nonparticipating perpetual royalty interest | $ 0 | Ìý | Ìý | Ìý | $ 0 | Ìý | Ìý | Ìý | $ 0 | $ 0 | Ìý |
Gross royalty interests (acre) | a | 370,737 | Ìý | Ìý | Ìý | 373,777 | Ìý | Ìý | Ìý | 370,737 | 373,777 | Ìý |
1/128th nonparticipating perpetual royalty interest | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Real Estate Properties [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Nonparticipating perpetual royalty interest rate | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 0.78125% | 0.78125% | Ìý |
Net Book Value | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
1/128th nonparticipating perpetual royalty interest | $ 0 | Ìý | Ìý | Ìý | $ 0 | Ìý | Ìý | Ìý | $ 0 | $ 0 | Ìý |
Gross royalty interests (acre) | a | 84,934 | Ìý | Ìý | Ìý | 85,414 | Ìý | Ìý | Ìý | 84,934 | 85,414 | Ìý |
Acquisition in conjunction with sale of 1/8th interest royalty acres | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Net Book Value | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Net royalty interests (acre) | a | 1,480 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 1,480 | Ìý | Ìý |
Acquisition of royalty interests | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 20,600 | Ìý | Ìý |
Average price per net royalty acre acquired (in dollars per acre) | $ / a | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 13,949 | Ìý | Ìý |
Additional real estate acquisitions | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Net Book Value | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Net royalty interests (acre) | a | 346 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 346 | Ìý | Ìý |
Acquisition of royalty interests | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 3,700 | Ìý | Ìý |
Average price per net royalty acre acquired (in dollars per acre) | $ / a | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 10,555 | Ìý | Ìý |
Sale of oil and gas royalty interests | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Net Book Value | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
Royalty interests sold | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 18,875 | $ 0 | $ 0 |