Condensed Consolidating Financial Statements (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Condensed Consolidating Cash Flow Statement
Net cash provided by (used in) operating activities	$ 171.4	$ 68.8
Investing activities:
Purchases of property, plant and equipment	(31.3)	(28.9)
Other investing activities, net	4.1rs_OtherInvestingActivities	(9.1)rs_OtherInvestingActivities
Net cash used in investing activities	(27.2)	(38.0)
Financing activities:
Net short-term debt borrowings	1.1	0.3
Proceed from long-term debt borrowings	363.0	160.0
Principal payments on long-term debt	(311.0)us-gaap_RepaymentsOfLongTermDebt	(141.7)us-gaap_RepaymentsOfLongTermDebt
Dividends paid	(31.7)us-gaap_PaymentsOfDividendsCommonStock	(27.1)us-gaap_PaymentsOfDividendsCommonStock
Share repurchases	(171.2)
Other financing activities, net	3.8rs_OtherFinancingActivities	8.7rs_OtherFinancingActivities
Net cash (used in) provided by financing activities	(146.0)	0.2
Effect of exchange rate changes on cash and cash equivalents	(2.8)	(1.0)
(Decrease) increase in cash and cash equivalents	(4.6)	30.0
Cash and cash equivalents at beginning of year	106.2	83.6
Cash and cash equivalents at end of period	101.6	113.6
Reportable legal entities \| Parent
Condensed Consolidating Cash Flow Statement
Net cash provided by (used in) operating activities	(41.0)	164.6
Investing activities:
Purchases of property, plant and equipment	(3.1)	(3.3)
Net repayments (advances) from subsidiaries	174.6	(134.6)
Other investing activities, net		0.1
Net cash used in investing activities	171.5	(137.8)
Financing activities:
Proceed from long-term debt borrowings	363.0	160.0
Principal payments on long-term debt	(310.3)	(141.3)
Dividends paid	(31.7)	(27.1)
Share repurchases	(171.2)
Other financing activities, net	4.4	8.7
Net cash (used in) provided by financing activities	(145.8)	0.3
(Decrease) increase in cash and cash equivalents	(15.3)	27.1
Cash and cash equivalents at beginning of year	41.9	19.7
Cash and cash equivalents at end of period	26.6	46.8
Reportable legal entities \| Guarantor Subsidiaries
Condensed Consolidating Cash Flow Statement
Net cash provided by (used in) operating activities	189.0	(94.5)
Investing activities:
Purchases of property, plant and equipment	(25.1)	(23.7)
Other investing activities, net	4.1	(9.2)
Net cash used in investing activities	(21.0)	(32.9)
Financing activities:
Principal payments on long-term debt	(0.7)	(0.4)
Net intercompany (repayments) borrowings	(162.5)	119.1
Net cash (used in) provided by financing activities	(163.2)	118.7
(Decrease) increase in cash and cash equivalents	4.8	(8.7)
Cash and cash equivalents at beginning of year	(8.3)	(0.8)
Cash and cash equivalents at end of period	(3.5)	(9.5)
Reportable legal entities \| Non-Guarantor Subsidiaries
Condensed Consolidating Cash Flow Statement
Net cash provided by (used in) operating activities	23.4	(1.3)
Investing activities:
Purchases of property, plant and equipment	(3.1)	(1.9)
Net cash used in investing activities	(3.1)	(1.9)
Financing activities:
Net short-term debt borrowings	1.1	0.3
Net intercompany (repayments) borrowings	(12.1)	15.5
Other financing activities, net	(0.6)
Net cash (used in) provided by financing activities	(11.6)	15.8
Effect of exchange rate changes on cash and cash equivalents	(2.8)	(1.0)
(Decrease) increase in cash and cash equivalents	5.9	11.6
Cash and cash equivalents at beginning of year	72.6	64.7
Cash and cash equivalents at end of period	78.5	76.3
Consolidating Adjustments
Investing activities:
Net repayments (advances) from subsidiaries	(174.6)	134.6
Net cash used in investing activities	(174.6)	134.6
Financing activities:
Net intercompany (repayments) borrowings	174.6	(134.6)
Net cash (used in) provided by financing activities	$ 174.6	$ (134.6)

The net cash outflow or inflow from other financing activities.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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The effect of exchange rate changes on cash balances in continuing operations held in foreign currencies.

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The increase (decrease) in cash associated with the entity's continuing operating, investing, and financing activities. While for technical reasons this element has no balance attribute, the default assumption is a debit balance consistent with its label.

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Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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