Significant Accounting Policies Income Taxes (Details)	12 Months Ended
	Dec. 31, 2016 USD ($)
Income Tax Policy [Abstract]
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries	$ 0
Deferred Tax Liability Not Recognized, Determination of Deferred Tax Liability is Not Practicable, Undistributed Earnings of Foreign Subsidiaries	the amount of the tax and credits is not practicable to determine
Undistributed Earnings of Foreign Subsidiaries	$ 267,100,000