Stockholder's Equity (Tables)

6 Months Ended

Jun. 30, 2017

Equity [Abstract]

Nonvested Stock Activity

The following table represents the nonvested stock activity for the six months ended June 30, 2017:

	Number of shares		Weighted average grant date fair value
Nonvested shares outstanding as of December 31, 2016	574,711		$	31.61
Granted	151,010		$	48.52
Vested	(178,196	)	$	28.93
Forfeited	(3,793	)	$	39.30
Nonvested shares outstanding as of June 30, 2017	543,732		$	37.13

Shares of Common Stock Issued During 2016 Under Employee Stock Purchase Plan

The table below details the shares of common stock issued during 2017:

	Number of shares	Per share price
Shares available as of December 31, 2016	189,611
Shares issued during the three months ended March 31, 2017	5,891	$	43.42
Shares issued during the three months ended June 30, 2017	4,152	$	51.21
Shares available as of June 30, 2017	179,568