XML 36 R23.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Derivative Financial Instruments (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2018
General Discussion of Derivative Instruments and Hedging Activities [Abstract] |
Summary Of Location And Amounts Of Derivative Fair Values In The Consolidated Balance Sheets | The following tables present the location and amounts of derivative fair values in the consolidated balance sheets and derivative gains or losses in the consolidated statements of operations:
| Derivative Fair Values
| September 30, 2018 |  | December 31, 2017
| (Amount in thousands)
Options sold - Other liabilities | $ | 589 |  |  | $ | 123 |
Total return swap - Other liabilities | 961 |  |  | 1,200 |
Total derivatives | $ | 1,550 |  |  | $ | 1,323 |
Schedule Of Derivative Gains And Losses In The Consolidated Statements Of Operations |
| Gains (Losses) Recognized in Income
| Three Months Ended September 30, |  | Nine Months Ended September 30,
| 2018 |  | 2017 |  | 2018 |  | 2017
| (Amounts in thousands)
Total return swap - Net realized investment (losses) gains | $ | 393 |  |  | $ | 118 |  |  | $ | 674 |  |  | $ | (2,535 | )
Options sold - Net realized investment (losses) gains | 2,141 |  |  | 557 |  |  | 7,872 |  |  | 1,857 |
Total | $ | 2,534 |  |  | $ | 675 |  |  | $ | 8,546 |  |  | $ | (678 | )

X
- Definition Schedule of Derivative Gains and Losses in the Consolidated Statements of Operations [Table Text Block] + References No definition available. + Details
Name: | mcy_ScheduleOfDerivativeGainsAndLossesInConsolidatedStatementsOfOperationsTableTextBlock
Namespace Prefix: | mcy_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_GeneralDiscussionOfDerivativeInstrumentsAndHedgingActivitiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration