14.	Stock-Based Compensation

In April 2008, the Company adopted the NBT Bancorp Inc. 2008 Omnibus Incentive Plan (the “Stock Plan”). Under the terms of the Stock Plan, options and other equity-based awards are granted to directors and employees to increase their direct proprietary interest in the operations and success of the Company. The Stock Plan assumed all prior equity-based incentive plans and any new equity-based awards are granted under the terms of the Stock Plan. Under terms of the Stock Plan, stock options are granted to purchase shares of the Company’s common stock at a price equal to the fair market value of the common stock on the date of the grant. Options granted have a vesting period of four years and terminate ten years from the date of the grant. Shares issued as a result of stock option exercises and vesting of restricted shares and stock unit awards are funded from the Company’s treasury stock. Restricted shares granted under the Plan vest after five years for employees and three years for non-employee directors. Restricted stock units granted under the Stock Plan may have different terms and conditions. Performance shares and units granted under the Stock Plan for executives may have different terms and conditions. Since 2011, the Company primarily grants restricted stock unit awards. Stock option grants since that time were reloads of existing grants.

The following table summarizes information concerning stock options outstanding:

(In thousands, except share and per share data)	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
Outstanding at January 1, 2017		230,174		$	24.35
Granted		1,500			40.63
Exercised		(118,844	)		25.94
Expired		(800	)		24.46
Outstanding at December 31, 2017		112,030		$	22.88		2.13	$	1,566
Exercisable at December 31, 2017		107,280		$	22.41		1.84	$	1,544
Expected to Vest		4,750		$	33.52		8.68	$	22

Total stock-based compensation expense for stock option awards totaled $0.1 million, $0.2 million and $0.2 million for the years ended December 31, 2017, 2016 and 2015, respectively. Cash proceeds, tax benefits and intrinsic value related to total stock options exercised is as follows:

	Years ended December 31,
(In thousands)	2017		2016		2015
Proceeds from stock options exercised	$	3,083	$	8,398	$	12,044
Tax benefits related to stock options exercised		650		1,223		952
Intrinsic value of stock options exercised		1,699		3,143		2,446
Fair value of shares vested during the year		329		105		63

The Company has outstanding restricted stock granted from various plans at December 31, 2017. The Company recognized $3.5 million, $4.2 million and $3.9 million in stock-based compensation expense related to these stock awards for the years ended December 31, 2017, 2016 and 2015, respectively. Tax benefits recognized with respect to restricted stock awards and stock units were $2.5 million, $2.9 million and $1.5 million for the years ended December 31, 2017, 2016 and 2015, respectively. Unrecognized compensation cost related to restricted stock awards and stock units totaled $4.8 million at December 31, 2017 and will be recognized over 2.1 years on a weighted average basis. Shares issued are funded from the Company’s treasury stock. The following table summarizes information for unvested restricted stock units outstanding as of December 31, 2017:

	Number of Shares			Weighted- Average Grant Date Fair Value
Unvested at January 1, 2017		613,163		$	22.62
Forfeited		(5,545	)		23.18
Vested		(198,652	)		22.34
Granted		125,772			36.15
Unvested at December 31, 2017		534,738		$	25.77

The Company has 2,813,597 securities remaining available to be granted as part of the Plan at December 31, 2017.