Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2016

Earnings Per Share [Abstract]

Schedule of reconciliation of the numerators and denominators used in the basic and diluted per-share computations

A reconciliation of the numerators and denominators used in the basic and diluted per-share computations is presented as follows for each class of common stock:

(dollars in thousands, except per share data)	Three months ended March 31,
	2016					2015
	Allocated net income (numerator)		Weighted shares (denominator)	Per-share amount		Allocated net income (numerator)		Weighted shares (denominator)	Per-share amount
Class A – Basic EPS:
Income available to Class A stockholders	$	45,520	46,189,068	$	0.99	$	38,515	46,189,068	$	0.83
Dilutive effect of stock-based awards	0		234,059	—		0		344,884	—
Assumed conversion of Class B shares	375		6,100,800	—		318		6,100,800	—
Class A – Diluted EPS:
Income available to Class A stockholders on Class A equivalent shares	$	45,895	52,523,927	$	0.87	$	38,833	52,634,752	$	0.74
Class B – Basic and diluted EPS:
Income available to Class B stockholders	$	375	2,542	$	148	$	318	2,542	$	125