XML 97 R64.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Derivative Financial Instruments (Schedule Of Derivative Gains And Losses In The Consolidated Statements Of Operations) (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Derivatives Not Designated as Hedging Instruments [Member] |  |  |
Derivative Financial Instruments [Line Items] |  |  |
Gain Recognized in Income | $ 4,056 | $ 3,247 | $ 10,232
Total Return Swap [Member] | Net realized investment gains [Member] | Derivatives Not Designated as Hedging Instruments [Member] |  |  |
Derivative Financial Instruments [Line Items] |  |  |
Gain Recognized in Income | 2,177 | 0 | 0
Interest rate swap agreements [Member] | Other comprehensive income (loss) [Member] | Derivatives Contracts for Cash Flow Hedges [Member] |  |  |
Derivative Financial Instruments [Line Items] |  |  |
Gain Recognized in Comprehensive Income | 0 | 0 | 1,139
Interest rate swap agreements [Member] | Other revenue (expense) [Member] | Derivatives Not Designated as Hedging Instruments [Member] |  |  |
Derivative Financial Instruments [Line Items] |  |  |
Gain Recognized in Income | 103 | 567 | 1,232
Equity contracts [Member] | Net realized investment gains [Member] | Derivatives Not Designated as Hedging Instruments [Member] |  |  |
Derivative Financial Instruments [Line Items] |  |  |
Gain Recognized in Income | $ 1,776 | $ 2,680 | $ 9,000

X
- Details
Name: | mcy_DerivativeFinancialInstrumentsLineItems
Namespace Prefix: | mcy_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration