Basis of Presentation and Significant Accounting Policies Basis of Presentation and Significant Accounting Policies (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax benefit	$ (27,886)	$ (28,913)	$ (52,568)	$ (55,842)
Increased in diluted weighted average common shares outstanding (in shares)	984	831	968	845
New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increased in diluted weighted average common shares outstanding (in shares)	178		175
New Accounting Pronouncement, Early Adoption, Effect [Member] | Income Tax Expense [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax benefit	$ 1,600		$ 4,200