Stock based Compensation

6 Months Ended

Jun. 30, 2015

(12) Stock-Based Compensation

In 2015, we granted the following shares of common stock, restricted stock and restricted stock units.

		Weighted-average
	Number	grant date		Aggregate		Vesting
	of shares	fair value		fair value		period

Common stock	23	$	58.17	$	1,323	None
Restricted stock	314		55.91		17,548	1 - 4 years
Restricted stock units	6		56.43		349	4 years

For common stock grants, we measure fair value based on the closing stock price of our common stock on the grant date and expense it on the grant date.

Certain awards of restricted stock and restricted stock units contain a performance condition based on the ultimate results for the applicable underwriting year. The number of such shares that vest could be higher or lower than initially granted. We measure fair value for these awards based on the closing price of our common stock on the grant date, and we recognize expense on a straight-line basis over the vesting period for those restricted stock awards or units expected to vest.

Certain of our executive officers were granted performance-based restricted stock in 2015. This restricted stock vests after three years and can vest from 0% to 200% of the initial shares granted. Vesting is based equally on an operating return on equity performance factor and a total shareholder return performance factor.

Under the terms of the Merger Agreement with Tokio Marine, all outstanding options, restricted stock and restricted stock units will be settled at the acquisition date. All awards with a performance condition will settle at 100% of the original shares granted.