Income Taxes Income Taxes (Tables)

9 Months Ended

Sep. 30, 2018

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The following table presents the provision for income taxes and the effective tax rates for the periods indicated.

	Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars in thousands)	2018			2017			2018			2017
Income before income tax expense	$	131,866		$	48,450		$	318,620		$	201,493
Income tax expense	30,401			18,806			78,410			69,358
Effective tax rate	23.1		%	38.8		%	24.6		%	34.4		%