Stock based Compensation

9 Months Ended

Sep. 30, 2012

Stock based Compensation [Abstract]

Stock based Compensation

(9) Stock-Based Compensation

In 2012, we granted the following shares of common stock, restricted stock awards, restricted stock units and stock options for the purchase of shares of our common stock. For all grants except stock options, we measure fair value based on the closing stock price of our common stock on the grant date. For stock options, we use the Black-Scholes single option pricing model to determine the fair value of an option on its grant date. The fair value of the common stock was expensed on the grant date. The fair value of the restricted stock awards, restricted stock units and stock options is being expensed over the vesting period.

		Weighted-average
	Number	grant date		Aggregate		Vesting
	of shares	fair value		fair value		period
Common stock	29	$	31.49	$	920	None
Restricted stock awards	313		31.20		9,758	2-4 years
Restricted stock units	13		30.60		403	4 years
Stock options	218		8.00		1,741	1-5 years