Stock Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock Compensation

	2013		2012		2011
Stock-based compensation expense	$	6,218	$	5,792	$	5,756
Income tax benefits	2,176		2,027		2,014

Stock Options Activity

	2013			2012			2011
Number of shares under stock options:
Options outstanding at beginning of year	3,000			92,499			201,674
Options granted	—			—			—
Options exercised	(3,000		)	(89,499		)	(107,575		)
Options canceled	—			—			(1,600		)
Options outstanding and exercisable at end of year	—			3,000			92,499
Weighted average exercise price:
Options exercised	$	12.41		$	10.63		$	12.25
Options canceled	$	—		$	—		$	11.80
Options outstanding and exercisable at end of year	$	—		$	12.41		$	10.69
Cash received from options exercised (in thousands)	$	37		$	951		$	1,318
Intrinsic value of options exercised (in thousands)	$	40		$	1,349		$	1,279
Intrinsic value of options outstanding (in thousands)	$	—		$	35		$	1,393

Restricted Stock Activity

	2013			2012			2011
Unvested shares at beginning of year	117,118			93,482			84,134
Shares granted	44,556			70,281			50,618
Shares canceled	(1,802		)	(790		)	(431		)
Shares vested	(55,456		)	(45,855		)	(40,839		)
Unvested shares at end of year	104,416			117,118			93,482
Weighted average fair value at grant date	$	26.04		$	25.83		$	23.06
Unrecognized compensation expense at end of year (in thousands)	$	1,199		$	1,428		$	932
Intrinsic value, unvested shares at end of year (in thousands)	$	2,943		$	2,824		$	2,407
Intrinsic value, shares vested during the year (in thousands)	$	1,363		$	1,173		$	934

Estimated Fair Value of Performance Shares Granted

	2013			2012			2011
Risk-free interest rate	0.4		%	0.3		%	1.2		%
Expected life, in years	3			3			3
Expected volatility	19.1		%	22.7		%	26.9		%
Dividend yield	4.6		%	4.5		%	4.7		%
Weighted average grant date fair value (per share)	$	23.30		$	26.06		$	20.79

Performance Share Activity

	2013			2012			2011
Opening balance of unvested performance shares	359,700			351,345			325,700
Performance shares granted	175,000			181,000			184,600
Performance shares canceled	(13,298		)	(4,544		)	(2,177		)
Performance shares vested	(176,718		)	(168,101		)	(156,778		)
Ending balance of unvested performance shares	344,684			359,700			351,345
Intrinsic value of unvested performance shares (in thousands)	$	9,717		$	8,672		$	9,047
Unrecognized compensation expense (in thousands)	$	3,651		$	3,800		$	2,991

Impact of the Market Condition on the Vested Performance Shares

	2013			2012			2011
Performance shares vested	176,718			168,101			156,778
Impact of market condition on shares vested	(176,718		)	(168,101		)	(15,678		)
Shares of common stock earned	—			—			141,100
Intrinsic value of common stock earned (in thousands)	$	—		$	—		$	3,633

Common Stock Repurchased

	2013		2012		2011
Stock repurchased from Ecova employees	$	405	$	599	$	464