XML 12 R50.htm IDEA: XBRL DOCUMENT v3.19.3

Proved and Unproved Oil and Gas Properties and Other Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Abandonment and impairment of unproved properties	$ 6,337	$ 9,055	$ 25,092	$ 26,615

X

- Definition

Impairment of Unproved Oil and Gas Properties

+ References

No definition available.

+ Details

Name:	sm_ImpairmentofUnprovedOilandGasProperties
Namespace Prefix:	sm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_FairValueDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration