(10) Share-based Compensation

The Company’s 2013 Stock Incentive Plan (as amended, the “2013 Equity Plan”) authorizes the issuance of various types of share-based awards to the Company’s employees, officers, directors, and other eligible participants. As of March 31, 2017, the total number of shares of the Company’s class A common stock authorized for issuance under the 2013 Equity Plan was 1,700,000 shares.

During the first quarter of 2017, stock options to purchase an aggregate of 90,000 shares of class A common stock were granted to certain Company employees pursuant to the 2013 Equity Plan. As of March 31, 2017, there were options to purchase 939,033 shares of class A common stock outstanding under the 2013 Equity Plan. As of March 31, 2017, there were 542,500 remaining shares of class A common stock authorized for future issuance under the 2013 Equity Plan.

The following table summarizes the Company’s stock option activity (in thousands, except per share data and years) for the three months ended March 31, 2017:

	Stock Options Outstanding
				Weighted Average		Aggregate		Weighted Average
				Exercise Price		Intrinsic		Remaining Contractual
	Shares			Per Share		Value		Term (Years)
Balance as of January 1, 2017		886		$	143.89
Granted		90			189.16
Exercised		(7	)		160.88	$	212
Forfeited/Expired		(30	)		201.25
Balance as of March 31, 2017		939		$	146.27
Exercisable as of March 31, 2017		374		$	137.67	$	19,119	7.4
Expected to vest as of March 31, 2017		565		$	151.97		21,073	7.9
Total		939		$	146.27	$	40,192	7.7

Stock options outstanding as of March 31, 2017 are comprised of the following range of exercise prices per share (in thousands, except per share data and years):

	Stock Options Outstanding at March 31, 2017
			Weighted Average		Weighted Average
			Exercise Price		Remaining Contractual
Range of Exercise Prices per Share	Shares		Per Share		Term (Years)
$117.85 - $120.00		30	$	118.63	7.1
$120.01 - $150.00		510	$	121.43	7.1
$150.01 - $180.00		209	$	167.41	7.9
$180.01 - $201.25		190	$	193.97	9.2
Total		939	$	146.27		7.7

An aggregate of 36,250 stock options with an aggregate fair value of $2.5 million vested during the three months ended March 31, 2017. Beginning January 1, 2017, the Company made an accounting policy election to prospectively account for forfeitures as they occur. Therefore, share-based compensation expense has not been adjusted for any estimated forfeitures. Prior periods have not been restated. The weighted average grant date fair value of stock option awards using the Black-Scholes pricing model was $77.31 for each share subject to a stock option granted during the three months ended March 31, 2017, based on the following assumptions:

	Three months ended
	March 31,
	2017
Expected term of options in years	6.3
Expected volatility		37.8	%
Risk-free interest rate		2.3	%
Expected dividend yield		0.0	%

No stock option awards were granted during the three months ended March 31, 2016.

For the three months ended March 31, 2017 and 2016, the Company recognized approximately $3.1 million and $1.5 million in share-based compensation expense from stock options granted under the 2013 Equity Plan. As of March 31, 2017, there was approximately $27.0 million of total unrecognized share-based compensation expense related to unvested stock options. The Company expects to recognize this remaining share-based compensation expense over a weighted average vesting period of approximately 2.3 years.

During the three months ended March 31, 2016, the Company was able to recognize and utilize tax deductions related to equity compensation in excess of compensation recognized for financial reporting that was generated under the 2013 Equity Plan. Accordingly, additional paid-in capital increased by $1.3 million during the three months ended March 31, 2016. Beginning January 1, 2017, excess tax benefits are no longer recognized as additional paid-in capital; instead, they are prospectively included within the provision for income taxes. Prior periods have not been restated.

During the three months ended March 31, 2016, the Company wrote off $1.6 million of deferred tax assets related to certain vested stock options that were no longer exercisable. Accordingly, additional paid-in capital decreased by $1.6 million during the three months ended March 31, 2016. No such adjustment was made during the three months ended March 31, 2017.

During the three months ended March 31, 2016, the Company paid $3.7 million to tax authorities related to the net exercise of a stock option under the 2013 Equity Plan. This payment resulted in a $3.7 million reduction to additional paid-in capital during the three months ended March 31, 2016. No net exercises of stock options were made during the three months ended March 31, 2017.