Condensed Guarantor and Non-Guarantor Financial Information, Cash Flow Statements (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net cash provided by operating activities	[1]	$ 112.5	$ 131.5
Cash flows from investing activities
Capital expenditures		(53.1)	(56.1)
Purchase of available for sale securities		(111.9)	(196.0)
Purchase of equity securities		(0.9)	0.0
Proceeds from disposition of available for sale securities		208.7	237.2
Cash payment for acquisition of manufacturing facility and related assets, net of cash received		(43.3)	0.0
Proceeds from disposal of property, plant and equipment		0.6	0.6
Intercompany loans receivable		0.0	0.0
Net cash provided by (used in) investing activities	[2]	0.1	(14.3)
Cash flows from financing activities
Repayment of capital lease		(0.5)	(0.2)
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		(6.9)	(4.5)
Repurchase of common stock		(31.9)	(66.7)
Cash dividends paid to Parent		0.0
Cash dividends and dividend equivalents paid		(28.5)	(26.4)
Intercompany loans payable		0.0	0.0
Net cash used in financing activities	[2]	(67.8)	(97.8)
Net increase in cash, cash equivalents, and restricted cash during the period		44.8	19.4
Cash, cash equivalents and restricted cash at beginning of period		64.3	67.7
Cash, cash equivalents and restricted cash at end of period		109.1	87.1
Consolidating Adjustments
Cash flows from operating activities:
Net cash provided by operating activities		(100.0)	0.0
Cash flows from investing activities
Capital expenditures		0.0	0.0
Purchase of available for sale securities		0.0	0.0
Purchase of equity securities		0.0
Proceeds from disposition of available for sale securities		0.0	0.0
Cash payment for acquisition of manufacturing facility and related assets, net of cash received		0.0
Proceeds from disposal of property, plant and equipment		0.0	0.0
Intercompany loans receivable		21.7	(104.8)
Net cash provided by (used in) investing activities		21.7	(104.8)
Cash flows from financing activities
Repayment of capital lease		0.0	0.0
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		0.0	0.0
Repurchase of common stock		0.0	0.0
Cash dividends paid to Parent		100.0
Cash dividends and dividend equivalents paid		0.0	0.0
Intercompany loans payable		(21.7)	104.8
Net cash used in financing activities		78.3	104.8
Net increase in cash, cash equivalents, and restricted cash during the period		0.0	0.0
Cash, cash equivalents and restricted cash at beginning of period		0.0	0.0
Cash, cash equivalents and restricted cash at end of period		0.0	0.0
Parent
Cash flows from operating activities:
Net cash provided by operating activities		87.5	(12.8)
Cash flows from investing activities
Capital expenditures		0.0	0.0
Purchase of available for sale securities		0.0	0.0
Purchase of equity securities		0.0
Proceeds from disposition of available for sale securities		0.0	0.0
Cash payment for acquisition of manufacturing facility and related assets, net of cash received		0.0
Proceeds from disposal of property, plant and equipment		0.0	0.0
Intercompany loans receivable		(20.2)	110.4
Net cash provided by (used in) investing activities		(20.2)	110.4
Cash flows from financing activities
Repayment of capital lease		0.0	0.0
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		(6.9)	(4.5)
Repurchase of common stock		(31.9)	(66.7)
Cash dividends paid to Parent		0.0
Cash dividends and dividend equivalents paid		(28.5)	(26.4)
Intercompany loans payable		0.0	0.0
Net cash used in financing activities		(67.3)	(97.6)
Net increase in cash, cash equivalents, and restricted cash during the period		0.0	0.0
Cash, cash equivalents and restricted cash at beginning of period		0.0	0.0
Cash, cash equivalents and restricted cash at end of period		0.0	0.0
Guarantor Subsidiaries
Cash flows from operating activities:
Net cash provided by operating activities		78.5	137.4
Cash flows from investing activities
Capital expenditures		(51.9)	(55.7)
Purchase of available for sale securities		(111.9)	(196.0)
Purchase of equity securities		(0.9)
Proceeds from disposition of available for sale securities		208.7	237.2
Cash payment for acquisition of manufacturing facility and related assets, net of cash received		0.0
Proceeds from disposal of property, plant and equipment		0.6	0.6
Intercompany loans receivable		(0.4)	0.0
Net cash provided by (used in) investing activities		44.2	(13.9)
Cash flows from financing activities
Repayment of capital lease		(0.5)	(0.2)
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		0.0	0.0
Repurchase of common stock		0.0	0.0
Cash dividends paid to Parent		(100.0)
Cash dividends and dividend equivalents paid		0.0	0.0
Intercompany loans payable		21.4	(104.8)
Net cash used in financing activities		(79.1)	(105.0)
Net increase in cash, cash equivalents, and restricted cash during the period		43.6	18.5
Cash, cash equivalents and restricted cash at beginning of period		61.3	65.1
Cash, cash equivalents and restricted cash at end of period		104.9	83.6
Non-Guarantor Subsidiaries
Cash flows from operating activities:
Net cash provided by operating activities		46.5	6.9
Cash flows from investing activities
Capital expenditures		(1.2)	(0.4)
Purchase of available for sale securities		0.0	0.0
Purchase of equity securities		0.0
Proceeds from disposition of available for sale securities		0.0	0.0
Cash payment for acquisition of manufacturing facility and related assets, net of cash received		(43.3)
Proceeds from disposal of property, plant and equipment		0.0	0.0
Intercompany loans receivable		(1.1)	(5.6)
Net cash provided by (used in) investing activities		(45.6)	(6.0)
Cash flows from financing activities
Repayment of capital lease		0.0	0.0
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares		0.0	0.0
Repurchase of common stock		0.0	0.0
Cash dividends paid to Parent		0.0
Cash dividends and dividend equivalents paid		0.0	0.0
Intercompany loans payable		0.3	0.0
Net cash used in financing activities		0.3	0.0
Net increase in cash, cash equivalents, and restricted cash during the period		1.2	0.9
Cash, cash equivalents and restricted cash at beginning of period		3.0	2.6
Cash, cash equivalents and restricted cash at end of period		$ 4.2	$ 3.5

[1] See Note 9 for adjustments made to arrive at our Consolidated Balance Sheet as of January 1, 2018 upon adopting ASC 606 (as defined in Note 1).

[2] See Note 13 for the supplemental disclosure on non-cash transactions.