Derivatives	9 Months Ended
Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives On September 20, 2018, the Company entered into the FX Contract for the JLT Transaction, to hedge the risk of appreciation of the GBP-denominated purchase price. The Company will purchase £5.2 billion at a contracted exchange rate. The settlement of the FX Contract is contingent upon the closing of the JLT Transaction. The all in contract exchange rate includes the cost of a liquidity premium (due to the size of the JLT Transaction) and a deal contingent feature, which together increased the exchange rate in the FX Contract to purchase the £5.2 billion by .0343. The all in contract exchange rate is fixed through March 29, 2019, increases by .00016 through June 28, 2019 and by 0.000145 each day thereafter until the JLT Transaction closes. The FX Contract is measured at fair value and the resulting gain or loss is recorded in the consolidated statements of income. The fair value was determined using the probability distribution approach, comparing the all in forward rate to the foreign exchange rate for possible dates the JLT Transaction is expected to close, discounted to the valuation date and adjusted for the fair value of the deal contingency feature. The fair value related to the deal contingency feature will decrease (and any unrealized loss increase or any unrealized gain decrease) as conditions to the closing are met. An unrealized loss of $100 million

Derivatives

On September 20, 2018, the Company entered into the FX Contract for the JLT Transaction, to hedge the risk of appreciation of the GBP-denominated purchase price. The Company will purchase £5.2 billion at a contracted exchange rate. The settlement of the FX Contract is contingent upon the closing of the JLT Transaction. The all in contract exchange rate includes the cost of a liquidity premium (due to the size of the JLT Transaction) and a deal contingent feature, which together increased the exchange rate in the FX Contract to purchase the £5.2 billion by

.0343. The all in contract exchange rate is fixed through March 29, 2019, increases by .00016 through June 28, 2019 and by 0.000145 each day thereafter until the JLT Transaction closes.

The FX Contract is measured at fair value and the resulting gain or loss is recorded in the consolidated statements of income. The fair value was determined using the probability distribution approach, comparing the all in forward rate to the foreign exchange rate for possible dates the JLT Transaction is expected to close, discounted to the valuation date and adjusted for the fair value of the deal contingency feature. The fair value related to the deal contingency feature will decrease (and any unrealized loss increase or any unrealized gain decrease) as conditions to the closing are met. An unrealized loss of $100 million