Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effective income tax	(34.30%)	(29.50%)
Deferred tax assets, net	$ 1,028,414		$ 1,049,408
Gross unrecognized tax benefits	20,700		21,502
Accrued interest and penalties on unrecognized tax benefits	11,800		12,200
Possible decrease in unrecognized tax benefits	$ 17,300
New Accounting Pronouncement, Early Adoption, Effect [Member] | Retained Earnings | Accounting Standards Update 2016-09, Excess Tax Benefit Component [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax assets, net			$ 18,600