XML 50 R44.htm IDEA: XBRL DOCUMENT v2.4.1.9
Summary of Significant Accounting Policies - Comprehensive Income (Loss) (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Statement Of Income And Comprehensive Income [Abstract]                      
Net income (loss) $ (58,271)us-gaap_NetIncomeLoss $ (1,903)us-gaap_NetIncomeLoss $ 1,898us-gaap_NetIncomeLoss $ 1,165us-gaap_NetIncomeLoss $ (37,498)us-gaap_NetIncomeLoss $ (24,034)us-gaap_NetIncomeLoss $ 129,705us-gaap_NetIncomeLoss $ (27,144)us-gaap_NetIncomeLoss $ (57,111)us-gaap_NetIncomeLoss $ 41,029us-gaap_NetIncomeLoss $ (100,060)us-gaap_NetIncomeLoss
Other comprehensive income (loss):                      
Realized gains on marketable securities reclassified to gain on sale of marketable securities, net of a benefit from income taxes of $9,318 and $2,757 in 2012 and 2013, respectively                   (5,120)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax (17,303)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax
Unrealized hedging gains, net of a benefit from income taxes of $161 in 2012                 0us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax 0us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax (298)us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
Unrealized gains on marketable securities, net of a provision for income taxes of $831 and $377 in 2012 and 2013, respectively                   702crk_OtherComprehensiveIncomeUnrealizedHoldingGainOnSecuritiesArisingDuringPeriodNetOfTax 1,543crk_OtherComprehensiveIncomeUnrealizedHoldingGainOnSecuritiesArisingDuringPeriodNetOfTax
Comprehensive income (loss)                 $ (57,111)us-gaap_ComprehensiveIncomeNetOfTax $ 36,611us-gaap_ComprehensiveIncomeNetOfTax $ (116,118)us-gaap_ComprehensiveIncomeNetOfTax