Business and Summary of Significant Accounting Principles (Impact of AWN NCI Acquisition) (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 02, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Noncontrolling Interest [Line Items]
Reduction of non-controlling interest		$ 1,138	$ 14,445	$ 281,803
Increase in deferred tax assets	$ 8,445
Fair value of consideration paid for acquisition of equity interest	303,831
Non-controlling Interests
Noncontrolling Interest [Line Items]
Reduction of non-controlling interest	268,364			271,521
Additional paid-in capital
Noncontrolling Interest [Line Items]
Reduction of non-controlling interest	$ 27,022	$ 1,138	$ 14,445	$ 10,282