Income Taxes Gross carryforwards (Details) $ in Millions	Dec. 31, 2016 USD ($)
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 248.8
Operating loss carryforwards, valuation allowance	193.6
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	265.9
Tax credit carryforwards, valuation allowance	265.9
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	997.7
Operating loss carryforwards, valuation allowance	787.7
Tax credit carryforwards	1,462.6
Tax credit carryforwards, valuation allowance	1,458.2
Capital Loss Carryforward [Member] | Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	19.7
Tax credit carryforwards, valuation allowance	$ 19.7