Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Data (Unaudited) [Abstract]

Summarized quarterly financial data

	Three Months Ended
	March 31		June 30		September 30		December 31
	(Dollars in thousands, except per share amounts)
2011
Net interest income	$	57,109	$	62,395	$	55,980	$	55,197
Provision for credit losses		7,068		—		—		—
Net earnings		16,600		21,038		22,383		21,712
Basic earnings per common share		0.16		0.20		0.21		0.21
Diluted earnings per common share		0.16		0.20		0.21		0.21
2010
Net interest income	$	73,339	$	64,214	$	62,615	$	59,149
Provision for credit losses		12,200		11,000		25,300		12,700
Net earnings		16,119		19,015		17,927		9,874
Basic earnings per common share		0.15		0.18		0.17		0.09
Diluted earnings per common share		0.15		0.18		0.17		0.09