Stock Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2017

Stock Incentive Plans [Abstract]

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

		Year Ended December 31,
	2017		2016		2015
Stock options	$	10	$	266	$	698
Restricted stock		19,092		28,603		30,146
	$	19,102	$	28,869	$	30,844

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

	Restricted Stock
	Number of	Weighted-Average
	Shares	Grant Date
	(000's)	Fair Value
Non-vested at December 31, 2016	987	$	58.98
Vested	(477)		63.15
Granted	247		69.78
Terminated	(59)		63.20
Non-vested at December 31, 2017	698	$	61.00