Stock-Based Compensation Stock Option Activity Rollforward (Details) - Successor [Member] $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, beginning of period | shares	15,889
Stock options granted during period | shares	3,251
Options exercised during period | shares	(1,920)
Option forfeited/expired during period | shares	(141)
Options outstanding, end of period | shares	17,079
Options Exercisable at End of Period | shares	12,103
Options Outstanding at beginning of period, Weighted Average Exercise Price | $ / shares	$ 48.43
Options Granted during period, Weighted Average Exercise Price | $ / shares	71.85
Options Exercised during period, Weighted Average Exercise Price | $ / shares	44.49
Options Forfeited/Expired during period, Weighted Average Exercise Price | $ / shares	56.63
Options Outstanding at end of period, Weighted Average Exercise Price | $ / shares	53.26
Options Exercisable at End of Period, Weighted Average Exercise Price | $ / shares	$ 48.14
Weighted Average Remaining Contractual Term	4 years 281 days
Options Exercisable at End of Period, Weighted Average Remaining Contractual Term	3 years 62 days
Aggregate Intrinsic Value | $	$ 909,699
Options Exercisable at End of Period, Aggregate Intrinsic Value | $	$ 582,700