Income Taxes Tax Rate (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

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

A reconciliation of the differences between the effective tax rate and the federal statutory tax rate for the years ended December 31 is as follows:

	2015	2014	2013
Federal statutory tax rate	35.0%	35.0%	35.0%
State income taxes, net of federal income tax benefit	3.9	3.3	3.5
Non-deductible employee stock purchase plan expense	0.3	0.3	0.3
Non-deductible meals and entertainment	0.3	0.4	0.3
Other, net	0.1	0.1	0.2
Effective tax rate	39.6%	39.1%	39.3%