Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Share-based Compensation [Abstract]

Transactions involving stock options under the terms of the LTSIP

Questar did not grant any stock options in the first quarter of 2013. Stock option transactions under the terms of the LTSIP are summarized below:

	Options Outstanding		Exercise Price Range					Weighted-Average Exercise Price
Balance at December 31, 2012	770,923		$	4.37	-	$	17.35	$	11.35
Exercised	(50,750	)				4.37		4.37
Balance at March 31, 2013	720,173		$	7.84	-	$	17.35	$	11.84

Options held under the LTSIP, by exercise price range

Options Outstanding									Options Exercisable
Range of exercise prices					Number outstanding at March 31, 2013	Weighted-average remaining term in years	Weighted-average exercise price		Number exercisable at March 31, 2013	Weighted-average exercise price
$	7.84	-	$	11.40	404,174	2.6	$	10.52	404,174	$	10.52
13.10		-	17.35		315,999	3.3	13.54		315,999	13.54
					720,173	2.9	$	11.84	720,173	$	11.84

Transactions involving restricted shares under the terms of the LTSIP

Transactions involving restricted shares under the terms of the LTSIP are summarized below:

	Restricted Shares Outstanding		Price Range					Weighted-Average Price
Balance at December 31, 2012	810,342		$	13.10	-	$	20.90	$	17.74
Granted	658					21.53		21.53
Vested	(338,750	)	13.10		-	19.39		17.54
Balance at March 31, 2013	472,250		$	13.10	-	$	21.53	$	17.89

Transactions involving performance shares under the terms of the LTSIP

Performance share transactions under the terms of the LTSIP are summarized below:

	Target Number of Performance Shares Outstanding	Grant-Date Fair Value Range					Weighted- Average Grant-Date Fair Value
Balance at December 31, 2012	264,867	$	18.23	-	$	25.42	$	21.94
Granted	126,606				39.62		39.62
Balance at March 31, 2013	391,473	$	18.23	-	$	39.62	$	27.66