Share-Based Compensation

3 Months Ended

Mar. 31, 2013

Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]

Share-Based Compensation

Share-Based Compensation

Share-based compensation expense for all share-based payment awards granted or modified is based on the estimated grant-date fair value. The Company recognizes these compensation costs on a straight-line basis over the requisite service period of the award, which is the option vesting term of four or five years for options granted prior to 2008 and four years for options granted subsequent to January 1, 2008, for only those shares expected to vest. The fair value of stock option awards is estimated using the Black-Scholes option pricing model with the grant-date assumptions and weighted-average fair values.

Under its 2005 Incentive Award Plan (the “Plan”), the Compensation Committee of the Company’s Board of Directors granted performance vesting restricted stock units to the Company’s senior management and key employees as follows:

	Grant Year
	2013	2012	2011
Three-year performance period ending December 31,	2015	2014	2013
Vesting shares, target	84,500	89,000	80,000
Vesting shares, maximum	190,125	200,250	120,000

The restricted stock units vest at the end of a three-year performance period beginning with the year of the grant, and then only if, and to the extent that, the Company’s cumulative underwriting income, and with respect to the 2012 and 2013 grants, target level of growth in net premiums written, during such three-year period achieves the threshold performance levels established by the Compensation Committee of the Company's Board of Directors.

The fair value of each restricted share grant was determined based on the market price on the grant date. Compensation cost has been recognized based on management’s best estimate that performance goals will be achieved. If such goals are not met, no compensation cost is recognized and any recognized compensation cost would be reversed. For the 2012 and 2011 grants, the achievement of the performance condition set by the Compensation Committee was no longer considered probable, and previously recognized compensation costs were reversed.