Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2014
Income Taxes [Line Items]
U.S. federal statutory rate				35.00%
Effective income tax rate	15.80%		20.30%	14.30%	17.60%
Income before income taxes, domestic operations				$ 33.7	$ 70.5
Income before income taxes, foreign operations				80.8	$ 41.9
Liabilities for uncertain income tax positions	$ 27.6			27.6							$ 37.6
Cash paid for income taxes				40.5
Prepaid tax payments	24.6			$ 24.6							$ 5.8
California Franchise Tax Board [Member]
Income Taxes [Line Items]
Income Tax Examination, Year under Examination						2013	2012
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions	0.1	$ 0.9
Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Income Tax Examination, Year under Examination						2013	2012
Tax Adjustments, Settlements, and Unusual Provisions	1.2	1.8
Liability for uncertain tax positions	$ 0.9	$ 9.3
Canada Revenue Agency [Member]
Income Taxes [Line Items]
Income Tax Examination, Year under Examination								2011	2010
New York City Department of Finance [Member]
Income Taxes [Line Items]
Income Tax Examination, Year under Examination								2011	2010	2009
New York State Division of Taxation and Finance [Member]
Income Taxes [Line Items]
Income Tax Examination, Year under Examination						2013	2012	2011