Commitments and Contingencies (Details) ft² in Thousands		12 Months Ended
	Jul. 10, 2015 USD ($) ft²	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Mar. 31, 2011 USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2016		$ 35,700,000
2017		25,600,000
2018		18,600,000
2019		10,300,000
2020		7,800,000
Thereafter		15,700,000
Total	$ 118,100,000	113,700,000
Rent expense		43,200,000	$ 46,000,000	$ 52,800,000
Lease extension term, total	20 years
Lease extension term increments	10 years
Square Feet of Leased Unit | ft²	63
Tenant Allowance	$ 6,000,000
Property and equipment, net		1,021,000,000	904,300,000
Purchase commitments		591,200,000
Accrual for estimated carrying charges or obsolete materials charges		18,000,000
Short-term debt		299,900,000	0
Senior notes		1,648,800,000	1,349,000,000
Indemnity-related and service-related escrows		36,200,000
Campus build-out commitments		3,500,000
Non-cancelable agreements		33,400,000
Long-term income tax payable		187,300,000	$ 177,500,000
Minimum [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Lease extension term increments	5 years
Maximum [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Lease extension term increments	10 years
Fixed Rate Note Due 2016 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 300,000,000					$ 300,000,000
Stated interest rate		3.10%					3.10%
Fixed Rate Note Due 2021 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 300,000,000					$ 300,000,000
Stated interest rate		4.60%					4.60%
Fixed Rate Notes Due 2021 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 300,000,000
Fixed rate note due 2020 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 300,000,000			$ 300,000,000
Stated interest rate		3.30%			3.30%
Fixed Rate Note Due 2024 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 350,000,000				$ 350,000,000
Stated interest rate		4.50%				4.50%
Fixed Rate Note Due 2025 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 300,000,000			$ 300,000,000
Stated interest rate		4.35%			4.35%
Fixed Rate Note Due 2041 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 400,000,000					$ 400,000,000
Stated interest rate		5.95%					5.95%
Fixed Rate Notes Due 2041 [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Long-term debt		$ 400,000,000
Construction in Progress [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Property and equipment, net		$ 45,600,000