Stockholders' Equity

Equity Incentive Plans

From time to time, the Company awards stock-based compensation under the 2006 Plan and 2015 SIP (each as defined in the 2017 Annual Report), including time-based restricted stock units (RSUs), performance-based restricted stock units (PSUs), stock appreciation rights (SARs), and non-qualified stock options (NQSOs). These awards may be issued to eligible employees and other plan participants, including the Company's executive officers.

Annual Awards

During fiscal year 2018, the Company elected to grant Annual RSUs and Annual PSUs under the 2015 SIP to key employees, including certain executive officers of the Company. These grants entitle the recipients to receive shares of the Company's common stock upon vesting. The vesting of Annual PSUs is subject to the achievement of pre-established Company performance criteria measured over the fiscal year during which they are granted, and to the extent the performance criteria has been met, vest in equal installments over three years thereafter. The Annual RSUs are subject only to time-based vesting criteria and vest in equal installments over three years following the date of grant. During the three months ended December 31, 2017, the Company granted no Annual PSUs and 1,782 Annual RSUs at a weighted-average grant date fair value of $72.86 per share. During the nine months ended December 31, 2017, the Company granted 54,090 Annual PSUs at a weighted-average grant date fair value of $68.44 per share and 133,302 Annual RSUs at a weighted-average grant date fair value of $67.67 per share. At December 31, 2017, the Company believes that the achievement of the performance criteria for the fiscal year 2018 Annual PSUs is probable. The Company recorded aggregate stock compensation expense, net of forfeitures, of $2,461 and $7,163 for the fiscal year 2018 Annual RSUs and Annual PSUs during the three and nine months ended December 31, 2017, respectively.

As of December 31, 2017, future unrecognized stock compensation expense for all Annual RSUs and Annual PSUs granted to date, excluding estimated forfeitures, is $12,420.

Long-Term Incentive Options (LTIP)

During fiscal year 2017, the Company approved the issuance of long-term incentive plan (LTIP) NQSOs under the 2015 SIP to the Company’s executive officers. If the Company achieves the minimum threshold performance criteria, and the recipient provides continuous service, the LTIP NQSOs will vest in equal installments over three years from the date of grant. Each option grants the recipient the right to purchase a specified number of shares of the Company's common stock at a fixed exercise price per share based on the closing price of the common stock on the date of grant. The Company measures stock compensation expense for LTIP NQSOs at the date of grant using the Black-Scholes option pricing model. This model estimates the fair value of the options based on a number of assumptions, such as expected option life, interest rates, the current fair market value and expected volatility, as well as dividend yield of the Company’s common stock.

In June 2017, the Company approved the grant of the FY 2018 LTIP NQSOs to the Company's executive officers, which will vest on March 31, 2020 if the recipient provides continuous service through that date and the Company achieves the minimum threshold performance criteria. As of December 31, 2017, the fair value of the FY 2018 LTIP NQSOs granted, less estimated forfeitures, was $4,600, with $420 and $909 expensed during the three and nine months ended December 31, 2017, respectively.

The following table presents the weighted-average valuation assumptions used for the recognition of stock-based compensation expense for the FY 2018 LTIP NQSOs granted:



Expected life (in years)	4.9
Expected volatility	38.73		%
Risk free interest rate	1.78		%
Dividend yield	—		%
Weighted-average exercise price	$	69.29
Weighted-average option value	$	25.03

As of December 31, 2017, future unrecognized stock compensation expense for all LTIP NQSOs granted to date, excluding estimated forfeitures, was $7,042.

Stock Repurchase Programs

In January 2015, the Company's Board of Directors approved a stock repurchase program which authorized the Company to repurchase up to $200,000 of its common stock in the open market or in privately negotiated transactions, subject to market conditions, applicable legal requirements, and other factors. In October 2017, the Company's Board of Directors authorized a new $335,000 stock repurchase program. Combined with the approximately $65,294 remaining approved amount from the previously-announced stock repurchase program, upon approval of the new repurchase program, the Company had the authority to repurchase up to an aggregate total of $400,294 of its common stock. The Company's repurchase programs do not obligate it to acquire any particular amount of common stock and may be suspended at any time at the Company's discretion.

During the nine months ended December 31, 2017, the Company repurchased 360,735 shares for $24,687 at an average price of $68.44 per share. Since inception through December 31, 2017, the Company has repurchased an aggregate of 2,380,584 shares for $159,393 at an average price of $66.96 per share, leaving the aggregate remaining approved amount at $375,607.

Subsequent to December 31, 2017, the Company repurchased 213,909 shares for $20,205 at an average price of $94.46 per share. Since inception through February 7, 2018, the Company has repurchased an aggregate of 2,594,493 shares for $179,598 at an average price of $69.22 per share, leaving the aggregate remaining approved amount at $355,402.

Retained Earnings

The following is a reconciliation of the Company's retained earnings as of December 31, 2017:



Balance as of March 31, 2017	$	819,589
Net income	93,779
Repurchase of common stock*	(24,683		)
Cumulative unrecognized excess tax benefit**	1,365
Balance as of December 31, 2017	$	890,050

*The remaining amount of 360,735 shares at par value $0.01 per share included in the total purchase price of $24,687, was recorded in common stock during the nine months ended December 31, 2017.

**Refer to Note 1, "General," in the section entitled "Recent Accounting Pronouncements" for further information regarding recording previously unrecognized excess tax benefits for share-based awards as a cumulative adjustment to retained earnings in response to the adoption of ASU No. 2016-09.