CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Operations and Comprehensive Income (Loss)
Gas marketing, related costs	$ 144,673	$ 256,836	$ 187,772

Costs related to marketing of natural gas and related products.

No definition available.

Name:	xec_GasMarketingRelatedCosts
Namespace Prefix:	xec_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration