Earnings per Share (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The following is a reconciliation of the numerator and denominator used in the basic and diluted EPS calculations:



	Year Ended
	December 31, 2012			December 31, 2011			December 31, 2010
Basic and diluted net income per share:

Numerator
Net income available to holders of Class A common stock	$	22,264		$	18,614		$	16,765
Earnings allocated to participating securities	(992		)	(1,100		)	(1,132		)
Earnings available for common stockholders	$	21,272		$	17,514		$	15,633

Denominator for basic net income per share of Class A common stock
Weighted average shares of Class A common stock	33,267			26,958			25,170

Denominator for diluted net income per share of Class A common stock
Weighted average shares of Class A common stock	33,267			26,958			25,170
Add dilutive effect of the following:
Restricted stock awards and units	1,318			874			919
Dilutive weighted average shares of Class A common stock	34,585			27,832			26,089

Basic income per share of Class A common stock	$	0.64		$	0.65		$	0.62

Diluted income per share of Class A common stock	$	0.62		$	0.63		$	0.60

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

Antidilution is the result of outstanding options exceeding those outstanding under the treasury stock method. Accordingly, the following shares were anti-dilutive and excluded from this calculation:



	Year Ended
	December 31, 2012	December 31, 2011	December 31, 2010
Weighted average IPO Options outstanding	1,559	1,634	1,742

Performance Shares Excluded [Table Text Block]

The potential dilutive effect of the Company's performance-based restricted stock awards and units were excluded from the calculation as the performance conditions had not been met:



	Year Ended
	December 31, 2012	December 31, 2011	December 31, 2010
Weighted average performance-based restricted stock awards and units	303	164	—

Weighted Average Class B Shares and New Class A Units Excluded [Table Text Block]

In addition, shares of Class B common stock and the underlying number of New Class A Units do not share in the earnings of the Company and are therefore not participating securities. Accordingly, basic and diluted earnings per share of Class B common stock and the underlying number of New Class A Units have not been presented. Accordingly, the following shares were excluded from this calculation:



	Year Ended
	December 31, 2012	December 31, 2011	December 31, 2010
Weighted average shares of Class B common stock and underlying New Class A Units outstanding	4,466	10,883	12,703