Committed Lines of Credit (Tables)

6 Months Ended

Jun. 30, 2017

Short-term Debt [Abstract]

Schedule of Line of Credit Facilities [Table Text Block]

Borrowings outstanding and interest rates of borrowings (excluding letters of credit) under the Company’s revolving committed line of credit were as follows as of June 30, 2017 and December 31, 2016 (dollars in thousands):

	June 30,			December 31,
	2017			2016
Borrowings outstanding at end of period	$	136,000		$	120,000
Letters of credit outstanding at end of period	$	56,703		$	34,353
Average interest rates at end of period	1.99		%	1.50		%