Earnings per Share (Tables)

3 Months Ended

Mar. 31, 2015

Earnings Per Share [Abstract]

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

The following table sets forth the computation of basic and diluted earnings per common share for the three months ended March 31, 2015 and 2014 (in thousands, except per share amounts):

	Three Months Ended
	March 31,
	2015		2014
Numerator:
Net income	$	23,904	$	40,004
Denominators:
Weighted average Class A common shares outstanding - Basic	55,826		54,841
Weighted average Class B common shares outstanding	1,002		1,609
Dilutive effect of employee stock-based awards	293		455
Weighted average shares - Diluted	57,121		56,905
Basic earnings per common share	$	0.43	$	0.73
Diluted earnings per common share	$	0.42	$	0.70

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

The following total number of Class A Common Stock shares issuable under the assumed exercise of stock-based awards computed based on the treasury stock method were excluded from the calculation of diluted earnings per common share, as the effect of including these shares would have been antidilutive (in thousands):

	Three Months Ended
	March 31,
	2015	2014
Antidilutive shares	503	186