Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Activity in Corporation's Active Stock Plans

A combined summary of activity in the Corporation’s active stock plans is presented in the following table.

						Non-Vested Stock Awards/Stock Units Outstanding				Stock Options Outstanding
	Shares Available for Grant			Director Deferred Stock Units Outstanding		Number of Shares		Weighted- Average Grant-Date Fair Value		Number of Shares			Weighted- Average Exercise Price
Balance, January 1, 2013		1,157,413			27,724		188,560	$	51.67		5,513,516		$	51.94
Authorized		2,293,660			—		—		—		—			—
Granted		(5,500	)		5,500		—		—		—			—
Stock options exercised		—			—		—		—		(662,224	)		51.63
Stock awards vested		—			—		—		—		—			—
Forfeited		30,375			—		—		—		(30,375	)		51.32
Cancelled/expired		—			—		—		—		—			—
Balance, June 30, 2013		3,475,948			33,224		188,560	$	51.67		4,820,917		$	51.99

Shares Issued in Connection with Stock Compensation Awards

Shares issued in connection with stock compensation awards along with other related information were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
New shares issued from available authorized shares		—		31,511		153,275		132,671
Issued from available treasury stock		266,799		—		508,949		7,640
Total		266,799		31,511		662,224		140,311
Proceeds from stock option exercises	$	13,743	$	1,669	$	34,189	$	7,211

Stock-Based Compensation Expense

Stock-based compensation expense was as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Stock options	$	1,968	$	2,158	$	3,966	$	4,359
Non-vested stock awards/stock units		345		355		689		709
Deferred stock units		330		330		330		330
Total	$	2,643	$	2,843	$	4,985	$	5,398

Unrecognized Stock-Based Compensation Expense

Unrecognized stock-based compensation expense at June 30, 2013 was as follows:

Stock options	$	13,374
Non-vested stock awards/stock units		2,245
Total	$	15,619