Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The denominators of the basic and diluted earnings per share computations are as follows (in thousands):

	Three Months Ended September 30,		Nine Months Ended September 30,
	2017	2016	2017	2016
Weighted-average common shares outstanding—basic and diluted	89,065	88,921	89,044	88,885