CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
REVENUES
Premiums earned, affiliated	$ 131,932	$ 119,117
LOSSES AND EXPENSES
Losses and settlement expenses, affiliated	88,691	72,479
Amortization of deferred policy acquisition costs, affiliated	24,429	21,950
Other expense, affiliated	$ 396	$ 87

From affiliates, amount of deferred policy acquisition costs charged to expense in the period, generally in proportion to related revenue earned, estimated gross profits, or over the customer relationship or some other period.

No definition available.

Name:	emci_DeferredPolicyAcquisitionCostAmortizationExpenseFromAffiliates
Namespace Prefix:	emci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration