Long-Term Debt - Additional Information (Details) - USD ($)						1 Months Ended	9 Months Ended
	Feb. 25, 2019	Feb. 12, 2019	Sep. 14, 2018	Oct. 31, 2016	Jun. 22, 2016	Aug. 31, 2013	Sep. 30, 2019	Sep. 12, 2018	Jun. 08, 2018	Jun. 05, 2014
Forward Starting Interest Rate Swap Agreement
Debt Instrument [Line Items]
Interest rate on notional value (as a percent)							3.14%
Interest rate swap agreements, notional amount										$ 150,000,000.0
2018 Refinancing Credit Agreement
Debt Instrument [Line Items]
Interest coverage ratio							3.00
Leverage ratio							3.25
Cash consideration							$ 500,000,000.0
Maximum leverage ratio permitted							3.75
Restrictive covenants, leverage ratio							3.50
2018 Refinancing Credit Agreement | LIBOR Rate
Debt Instrument [Line Items]
Letters of credit subject to financial covenant restrictions							$ 300,000,000.0
2018 Refinancing Credit Agreement | LIBOR Rate | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							1.00%
2018 Refinancing Credit Agreement | LIBOR Rate | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							1.875%
2018 Refinancing Credit Agreement | Base Rate | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.00%
2018 Refinancing Credit Agreement | Base Rate | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.875%
2016 Refinancing Credit Agreement
Debt Instrument [Line Items]
Deferred financing cost					$ 3,000,000
2016 Refinancing Credit Agreement | Federal Funds Effective Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.50%
2016 Refinancing Credit Agreement | LIBOR Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							1.00%
2016 Refinancing Credit Agreement | Base Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.00%
2016 Refinancing Credit Agreement | Base Rate | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.00%
2016 Refinancing Credit Agreement | Base Rate | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.75%
2016 Refinancing Credit Agreement | Alternative Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							1.75%
2016 Refinancing Credit Agreement | Alternative Rate | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							0.75%
2016 Refinancing Credit Agreement | Alternative Rate | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate							1.75%
Bridge Loan | 2018 Refinancing Credit Agreement
Debt Instrument [Line Items]
Revolving credit facility, amount									$ 2,500,000,000
Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount			$ 2,500,000,000
Increase in interest rate		0.25%
Senior Notes | Floating Rate Notes, due 2021
Debt Instrument [Line Items]
Debt instrument face amount			$ 500,000,000.0
Debt instrument, term			1 year
Debt issuance price (as a percent)			100.00%
Floating interest rate (as a percent)								3.3815%
Deferred financing cost			$ 3,500,000
Senior Notes | Floating Rate Notes, due 2021 | LIBOR Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.05%
Senior Notes | 4.15% Senior Notes, due 2024
Debt Instrument [Line Items]
Debt instrument face amount			$ 750,000,000.0
Debt issuance price (as a percent)			99.805%
Deferred financing cost			$ 7,400,000
Stated interest rate (as a percent)			4.15%				4.15%
Senior Notes | 4.70% Senior Notes, due 2028
Debt Instrument [Line Items]
Debt issuance price (as a percent)			99.889%
Deferred financing cost			$ 10,600,000
Stated interest rate (as a percent)			4.70%				4.70%
Senior Notes | 3.45% Senior Notes, due 2026
Debt Instrument [Line Items]
Debt instrument face amount				$ 750,000,000.0
Debt issuance price (as a percent)				99.965%
Deferred financing cost				$ 2,700,000
Stated interest rate (as a percent)				3.45%			3.45%
Senior Notes | 4.375% Senior Notes, due 2023
Debt Instrument [Line Items]
Debt instrument face amount						$ 250,000,000.0
Debt issuance price (as a percent)						99.879%
Deferred financing cost						$ 2,600,000
Stated interest rate (as a percent)						4.375%	4.375%
Senior Notes | Senior Notes Due 2028 and Senior Notes
Debt Instrument [Line Items]
Debt instrument face amount			$ 1,250,000,000.0
Stated interest rate (as a percent)			4.70%
Senior Notes | 2018 Refinancing Credit Agreement | Letter of Credit
Debt Instrument [Line Items]
Revolving credit facility, amount							$ 29,300,000
Letters of credit subject to financial covenant restrictions							$ 656,000,000.0
Line of Credit | 2018 Refinancing Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Revolving credit facility, amount									1,200,000,000
Uncommitted accordion feature									600,000,000.0
Line of Credit | 2018 Refinancing Credit Agreement | Letter of Credit
Debt Instrument [Line Items]
Revolving credit facility, amount									450,000,000.0
Line of Credit | 2018 Refinancing Credit Agreement | Term Loan
Debt Instrument [Line Items]
Revolving credit facility, amount									350,000,000.0
Line of Credit | 2018 Refinancing Credit Agreement | Delayed Draw Term Loan
Debt Instrument [Line Items]
Revolving credit facility, amount									400,000,000.0
Commitment fee	0.175%
Line of Credit | 2018 Refinancing Credit Agreement | Swing Line Sub Facility
Debt Instrument [Line Items]
Revolving credit facility, amount									$ 75,000,000.0
Line of Credit | 2016 Refinancing Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility loan term, years					5 years