Debt and Credit Agreements Schedule of Financial Covenants in Credit Agreement (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Line of Credit Facility [Abstract]

Schedule of Financial Covenants in Credit Agreement [Table Text Block]

Interest coverage ratio (not less than): 1	5.00x
Leverage ratio (not greater than): 2	3.50x

1 The interest coverage ratio is defined as EBITDA, as defined in the Credit Agreement, to net interest expense for the four quarters then ended.

2 The leverage ratio is defined as debt as of the last day of such fiscal quarter to EBITDA, as defined in the Credit Agreement, for the four quarters then ended. The leverage ratio may be changed to not more than 4.00 to 1 at our election for four consecutive fiscal quarters, beginning with the fiscal quarter in which there is an occurrence of one or more acquisitions with an aggregate purchase price of at least $200.0.