Derivative Financial Instruments (Details) £ in Millions, $ in Millions		12 Months Ended
	Jun. 29, 2016 USD ($)	Dec. 31, 2016 GBP (£) item	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) item
Derivative [Line Items]
Number of contracts with credit risk related contingent features | item		0		0
Agreements terminated during the period, notional amount | $	$ 200.0
Weighted average fixed rate, terminated agreements	2.40%
Unrealized loss recognized upon termination | $	$ 4.9
Other Expense [Member]
Derivative [Line Items]
Loss on ineffectiveness | $			$ 0.4
2018 and 2019
Derivative [Line Items]
New agreements during the period, notional amount | £		£ 550.0
2018
Derivative [Line Items]
New agreements during the period, notional amount | £		250.0
2019
Derivative [Line Items]
New agreements during the period, notional amount | £		300.0
2020
Derivative [Line Items]
New agreements, initial notional amount, later increased | £		250.0
New agreements during the period, notional amount | $	$ 200.0
Weighted Average Fixed Rate	2.52%
2022
Derivative [Line Items]
New agreements during the period, notional amount		£ 500.0	$ 400.0
Derivatives In Cash Flow Hedging Relationships | 2017 | U.S.
Derivative [Line Items]
Weighted Average Fixed Rate		2.53%		2.53%
Derivative Liability, Notional Amount | $				$ 1,000.0
Derivatives In Cash Flow Hedging Relationships | 2017 | U.K.
Derivative [Line Items]
Weighted Average Fixed Rate		0.82%		0.82%
Derivative Liability, Notional Amount | £		£ 550.0
Derivatives In Cash Flow Hedging Relationships | 2018 | U.S.
Derivative [Line Items]
Weighted Average Fixed Rate		2.17%		2.17%
Derivative Liability, Notional Amount | $				$ 1,150.0
Derivatives In Cash Flow Hedging Relationships | 2018 | U.K.
Derivative [Line Items]
Weighted Average Fixed Rate		0.82%		0.82%
Derivative Liability, Notional Amount | £		£ 550.0
Derivatives In Cash Flow Hedging Relationships | 2019 | U.S.
Derivative [Line Items]
Weighted Average Fixed Rate		2.06%		2.06%
Derivative Liability, Notional Amount | $				$ 1,000.0
Derivatives In Cash Flow Hedging Relationships | 2019 | U.K.
Derivative [Line Items]
Weighted Average Fixed Rate		0.90%		0.90%
Derivative Liability, Notional Amount | £		£ 550.0
Derivatives In Cash Flow Hedging Relationships | 2020 | U.S.
Derivative [Line Items]
Weighted Average Fixed Rate		2.06%		2.06%
Derivative Liability, Notional Amount | $				$ 1,000.0
Derivatives In Cash Flow Hedging Relationships | 2020 | U.K.
Derivative [Line Items]
Weighted Average Fixed Rate		0.94%		0.94%
Derivative Liability, Notional Amount | £		£ 500.0
Derivatives In Cash Flow Hedging Relationships | 2021 | U.S.
Derivative [Line Items]
Weighted Average Fixed Rate		1.46%		1.46%
Derivative Liability, Notional Amount | $				$ 400.0
Derivatives In Cash Flow Hedging Relationships | 2021 | U.K.
Derivative [Line Items]
Weighted Average Fixed Rate		0.94%		0.94%
Derivative Liability, Notional Amount | £		£ 500.0
Derivatives In Cash Flow Hedging Relationships | 2022 | U.S.
Derivative [Line Items]
Weighted Average Fixed Rate		1.46%		1.46%
Derivative Liability, Notional Amount | $				$ 400.0
Derivatives In Cash Flow Hedging Relationships | 2022 | U.K.
Derivative [Line Items]
Weighted Average Fixed Rate		0.94%		0.94%
Derivative Liability, Notional Amount | £		£ 500.0