Fair Value - Inputs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Series C preferred stock
Fair Value
Estimated fair value of Visa preferred shares	$ 25.0
eService | Weighted Average Cost of Capital
Fair Value
Redeemable non-controlling interest, measurement input (as a percent)	15.50%
eService | Minimum | Growth Rate
Fair Value
Redeemable non-controlling interest, measurement input (as a percent)	3.00%
eService | Maximum | Growth Rate
Fair Value
Redeemable non-controlling interest, measurement input (as a percent)	17.80%