Significant Accounting Policies Update (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment per unit value minimum	$ 1,000	$ 1,000
Property and equipment useful life minimum		1 year
MUFG
Property, Plant and Equipment [Line Items]
Ownership percent	20.00%	20.00%
Equity method investment	$ 36,000,000.0	$ 36,000,000.0
Network assets
Property, Plant and Equipment [Line Items]
Useful life		5 years	4 years
Decrease to deprecation expense	9,200,000	$ 16,700,000
Increase to net income	$ 7,600,000	$ 13,900,000
Increase to net income (in dollars per share)	$ 0.05	$ 0.09