Stockholder's Equity (Tables)

9 Months Ended

Sep. 30, 2019

Equity [Abstract]

Share Grants Activity

The following table represents the share grants activity for the nine months ended September 30, 2019: 

	Restricted stock				Options
	Number of shares		Weighted average grant date fair value		Number of shares		Weighted average grant date fair value
Share grants outstanding as of December 31, 2018	574,285		$	49.68	161,807		$	38.08
Granted	163,995		$	109.65	—		$	—
Vested or exercised	(220,691	)	$	45.02	(56,738	)	$	31.64
Share grants outstanding as of September 30, 2019	517,589		$	69.50	105,069		$	40.64

Shares of Common Stock Issued Under Employee Stock Purchase Plan

The table below details the shares of common stock issued during 2019: 

	Number of shares	Per share price
Shares available as of December 31, 2018	152,344
Shares issued during the three months ended March 31, 2019	5,357	$	89.19
Shares issued during the three months ended June 30, 2019	4,301	$	105.36
Shares issued during the three months ended September 30, 2019	5,360	$	113.60
Shares available as of September 30, 2019	137,326