The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction and being repurchased. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

No definition available.

Indebtedness (Narrative) (Details)	12 Months Ended										12 Months Ended					12 Months Ended	6 Months Ended		12 Months Ended					12 Months Ended
Indebtedness (Narrative) (Details)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 Conversion Event, One	Dec. 31, 2014 Conversion Event, Two	Dec. 31, 2014 Senior Unsecured Term Loan Due January 15, 2020, 1.056% [Member] EUR (€)	Dec. 31, 2014 Revolving Credit Facility [Member] USD ($)	Dec. 31, 2014 Senior Unsecured Term Loan Due May 2, 2016, 4.5% USD ($)	Dec. 31, 2014 Senior Unsecured Term Loan Due May 2, 2016, 4.5% EUR (€)	Dec. 31, 2013 Senior Unsecured Term Loan Due May 2, 2016, 4.5% USD ($)	Dec. 31, 2014 1 1/4percent Convertible Senior Subordinated Notes Due December 15, 2036 USD ($)	Dec. 31, 2013 1 1/4percent Convertible Senior Subordinated Notes Due December 15, 2036 USD ($)	Jun. 30, 2014 1 1/4percent Convertible Senior Subordinated Notes Due December 15, 2036 USD ($)	Dec. 31, 2014 5 7/8% Senior Notes due 2021 USD ($)	Dec. 31, 2013 5 7/8% Senior Notes due 2021 USD ($)	Dec. 31, 2014 5 7/8% Senior Notes due 2021 Interest Accrual, Option Two	Jun. 30, 2014 Term Loan Facility USD ($)	Jun. 30, 2014 Term Loan Facility Future Periodic Payment USD ($)	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Line of Credit [Member] Interest Accrual, Option Two	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Line of Credit [Member] Interest Accrual, Option Three	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Line of Credit [Member] Minimum Interest Accrual, Option One	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Line of Credit [Member] Maximum Interest Accrual, Option One	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Term Loan Facility USD ($)	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Variable Basis, Additional Margin Line of Credit [Member] Minimum Interest Accrual, Option Three	Dec. 31, 2014 Amended and Restated Credit Facility Agreement [Member] Variable Basis, Additional Margin Line of Credit [Member] Maximum Interest Accrual, Option Three	Jan. 15, 2015 Subsequent Event Senior Unsecured Term Loan Due January 15, 2020, 1.056% [Member] USD ($)	Jan. 15, 2015 Subsequent Event Senior Unsecured Term Loan Due January 15, 2020, 1.056% [Member] EUR (€)	Jun. 30, 2014 Revolving Credit Facility [Member] Line of Credit [Member] USD ($)	Dec. 31, 2014 Revolving Credit Facility [Member] Amended and Restated Credit Facility Agreement [Member] Line of Credit [Member] USD ($)
Debt Instrument [Line Items]
Carrying amount of the equity component												$ 54,300,000
Debt Interest Rate								4.50%	4.50%	4.50%	1.25%	1.25%		5.875%	5.875%											1.056%	1.056%
Effective interest rate		6.10%	6.10%
Interest Paid	68,400,000us-gaap_InterestPaid	66,400,000us-gaap_InterestPaid	70,000,000us-gaap_InterestPaid
Debt maturity date											Dec. 15, 2036
Conversion event, percent of closing sales price to conversion price											120.00%
Convertible senior subordinated notes conversion price													$ 40.27
Convertible senior subordinated notes, conversion rate											24.8295
Convertible senior subordinated notes principal amount per note											1,000
Debt repurchased											49,700,000
Trading period of qualifying event				20 days	5 days
Trading period in which qualifying event must occur				30 days
Window for conversion					5 days
Convertible notes converted											151,500,000	100,000
Debt conversion, shares issued											1,437,465	286
Excess conversion value of the notes											81,000,000	100,000
Repayments of Convertible Debt	201,200,000us-gaap_RepaymentsOfConvertibleDebt	0us-gaap_RepaymentsOfConvertibleDebt	0us-gaap_RepaymentsOfConvertibleDebt
Senior Notes								242,000,000	200,000,000.0	275,000,000				300,000,000	300,000,000											232,400,000	200,000,000.0
Debt Instrument, Face Amount														300,000,000.0
Line of Credit Facility, Maximum Borrowing Capacity							404,400,000																355,000,000					600,000,000	800,000,000
Debt Instrument, Periodic Payment																	5,000,000	10,000,000
Debt Instrument, Basis Spread on Variable Rate																0.50%			0.50%	1.00%	1.00%	2.00%		0.00%	0.50%
Line of Credit Facility, Remaining Borrowing Capacity	750,600,000	600,000,000
Unused borrowing capacity						200,000,000.0
Credit Facility	404,400,000us-gaap_LineOfCredit	360,000,000us-gaap_LineOfCredit
Outstanding letters of credit	$ 18,500,000	$ 16,700,000