Fair Value - Summary (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value
Cash equivalents	$ 103,987	$ 110,537
Contingent consideration	8,075	3,957
Total	1,081,338	262,760
Blueapple
Fair Value
Redeemable non-controlling interest	815,417
eService
Fair Value
Redeemable non-controlling interest	153,859	148,266
Level 1
Fair Value
Cash equivalents	103,987	110,537
Total	103,987	110,537
Level 3
Fair Value
Contingent consideration	8,075	3,957
Total	977,351	152,223
Level 3 | Blueapple
Fair Value
Redeemable non-controlling interest	815,417
Level 3 | eService
Fair Value
Redeemable non-controlling interest	$ 153,859	$ 148,266