Debt (Term Loans Under The Senior Credit Agreement) (Narrative) (Details) - USD ($)		3 Months Ended		6 Months Ended
	Jun. 10, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Debt Instrument [Line Items]
Repayment of term loans				$ 15,000,000	$ 295,500,000
Deferred financing fees		$ 4,626,000	$ 4,278,000	9,170,000	$ 8,516,000
Debt instrument, principal balance		8,270,000,000		8,270,000,000		$ 7,870,000,000
2012-1 Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 200,000,000		$ 200,000,000
Debt instrument, maturity date				May 09, 2017
Coupon rate of notes		2.69%		2.69%
Deferred financing fees		$ 2,700,000		$ 2,700,000
Quarterly payments, first eight quarters				2,500,000
Quarterly payments, next four quarters				3,800,000
Quarterly payments, thereafter				5,000,000
Repayment of term loans		3,800,000		7,500,000
Debt instrument, principal balance		165,000,000		165,000,000		172,500,000
2014 Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,500,000,000		$ 1,500,000,000
Debt instrument, maturity date				Mar. 24, 2021
Term Loan, percentage of par value		99.75%		99.75%
Coupon rate of notes		3.25%		3.25%
Deferred financing fees		$ 12,900,000		$ 12,900,000
Quarterly payments				3,800,000
Repayment of term loans		3,800,000		7,500,000
Debt instrument, principal balance		1,485,000,000		1,485,000,000		$ 1,492,500,000
2015 Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 500,000,000	$ 500,000,000		$ 500,000,000
Debt instrument, maturity date				Jun. 10, 2022
Term Loan, percentage of par value	99.00%
Coupon rate of notes		3.25%		3.25%
Repayment of term loans				$ 1,300,000
Deferred financing fees				5,100,000
Debt instrument, principal balance		$ 500,000,000		$ 500,000,000
Base Rate [Member] | 2014 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				1.50%
Base rate floor				1.75%
Base Rate [Member] | 2015 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate	1.50%
Base rate floor	1.75%
Eurodollar [Member] | 2014 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				2.50%
Eurodollar rate floor				0.75%
Eurodollar [Member] | 2015 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate	2.50%
Eurodollar rate floor	0.75%
Minimum [Member] | Base Rate [Member] | 2012-1 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				1.00%
Minimum [Member] | Eurodollar [Member] | 2012-1 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				2.00%
Maximum [Member] | Base Rate [Member] | 2012-1 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				1.50%
Maximum [Member] | Eurodollar [Member] | 2012-1 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate				2.50%