XML 19 R10.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Fair Value Option | 6 Months Ended
--- | ---
Jun. 30, 2013
Fair Value Option [Abstract] |
Fair Value Option | Fair Value Option Gains and losses due to changes in fair value for items measured at fair value pursuant to application of the fair value option are included in net realized investment (losses) gains in the Company’s consolidated statements of operations, while interest and dividend income on investment holdings are recognized on an accrual basis on each measurement date and are included in net investment income in the Company’s consolidated statements of operations. The primary reasons for electing the fair value option were simplification and cost-benefit considerations as well as expansion of use of fair value measurement consistent with the long-term measurement objectives of the FASB for accounting for financial instruments. The following table presents (losses) gains due to changes in fair value of investments that are measured at fair value pursuant to application of the fair value option:
| Three Months Ended June 30, |  | Six Months Ended June 30,
| 2013 |  | 2012 |  | 2013 |  | 2012
| (Amounts in thousands)
Fixed maturity securities | $ | (59,562 | ) |  | $ | 9,812 |  |  | $ | (69,973 | ) |  | $ | 30,815 |
Equity securities | (19,003 | ) |  | (33,972 | ) |  | 35,023 |  |  | (5,476 | )
Short-term investments | (161 | ) |  | (628 | ) |  | (309 | ) |  | (784 | )
Total | $ | (78,726 | ) |  | $ | (24,788 | ) |  | $ | (35,259 | ) |  | $ | 24,555 |

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

X
- Definition The entire disclosure for a company's election to apply the fair value option for measurement and reporting of eligible financial assets and liabilities (as defined), as well as certain other eligible items (as defined) included in the statement of financial position, whether such option is elected for a single eligible item or a group of similar eligible items and is in addition to other disclosures concerning fair value which the company may be required to provide. Such disclosure might be expected to include: (1) for items included in the statement of financial position: (a) the reasons for electing a fair value option for each eligible item or group of similar eligible items; (b) if the fair value option is elected for some but not all eligible items within a group of similar eligible items: (i) a description of those similar items and the reasons for partial election and (ii) information of how the group of similar items relates to individual balance sheet line items; (c) for each line item in the statement of financial position that includes an item or items for which the fair value option has been elected: (i) information of how each line item in the statement of financial position relates to major categories of assets and liabilities presented in accordance with other fair value disclosures and (ii) the aggregate carrying amount of ineligible items included in each line item in the balance sheet, if any; (d) the difference between the aggregate fair value and the aggregate unpaid principal balance (assuming contractual principal amounts and fair value option elected) of: (i) loans and long-term receivables (other than securities otherwise reported at fair value) and (ii) long-term debt instruments; (e) for loans held as assets for which the fair value option has been elected: (i) the aggregate fair value of loans that are 90 days or more past due, (ii) if the policy is to recognize interest income separately from other changes in fair value, the aggregate fair value of loans in nonaccrual status, and (iii) the difference between the aggregate fair value and the aggregate unpaid principal balance for loans that are 90 days or more past due, in nonaccrual status, or both; (f) for investments that would have been accounted for under the equity method if the entity had not chosen to apply the fair value option, the information required for such investments, if material either individually or in the aggregate; (2) for items included in the income statement: (a) the amounts of gains and losses from fair value changes included in earnings and in which line in the income statement those gains and losses are reported whether or not combined with gains and losses from items required to be accounted for at fair value; (b) a description of how interest and dividends are measured and where they are reported in the income statement; (c) for loans and other receivables held as assets: (i) the estimated amount of gains or losses included in earnings attributable to changes in instrument-specific credit risk and (ii) how the gains or losses attributable to changes in instrument-specific credit risk were determined; (d) for liabilities with fair values that have been significantly affected during the reporting period by changes in the instrument-specific credit risk: (i) the estimated amount of gains and losses from fair value changes included in earnings that are attributable to changes in the instrument-specific credit risk, (ii) qualitative information about the reasons for those changes, and (iii) how the gains and losses attributable to changes in instrument-specific credit risk were determined; and (3) certain other disclosures as required or determined to be provided. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 32 -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14217-108612 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14210-108612 + Details
Name: | us-gaap_FairValueOptionTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration