Net Earnings Per Common Share - Calculation of Basic and Diluted Net Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator
Net (loss) earnings available to common stockholders		$ 87.8	$ 49.6	$ 44.6	$ 152.0	[1]
Distributed and allocated undistributed net loss to non-vested restricted stockholders		(0.6)	(0.1)	(0.2)	(1.1)
Distributed and allocated undistributed net earnings to common stockholders		87.2	49.5	44.4	150.9
Distributed net (loss) earnings - dividends paid to common stockholders		(30.4)	(31.5)	(61.4)	(56.7)
Allocation of undistributed net (loss) earnings to common stockholders		$ 56.8	$ 18.0	$ (17.0)	$ 94.2
Denominator
Weighted average number of common shares outstanding - basic		192.5	195.6	192.9	195.4
Basic net earnings per common share:
Distributed net earnings to common stockholders (in dollars per share)		$ 0.16	$ 0.16	$ 0.32	$ 0.29
Allocated undistributed net earnings (loss) to common stockholders (in dollars per share)		0.29	0.09	(0.09)	0.47
Net earnings (loss) per common share - basic (in dollars per share)	[2]	$ 0.45	$ 0.25	$ 0.23	$ 0.76
Numerator
Distributed and allocated undistributed net earnings to common stockholders		$ 87.2	$ 49.5	$ 44.4	$ 150.9
Add: Allocated undistributed net earnings to unvested restricted stockholders		0.4	0.1	0.0	0.7
Less: Undistributed net earnings (loss) reallocated to non-vested restricted stockholders		(0.4)	(0.1)	0.0	(0.7)
Net earnings available to common stockholders - diluted		$ 87.2	$ 49.5	$ 44.4	$ 150.9
Denominator
Weighted average number of common shares outstanding - basic		192.5	195.6	192.9	195.4
Effect of contingently issuable shares (in shares)		0.7	0.9	0.7	0.8
Effect of unvested restricted stock units (in shares)		1.0	1.0	1.0	1.0
Weighted average number of common shares outstanding - diluted under two-class		194.2	197.5	194.6	197.2
Effect of unvested restricted stock - participating security (in shares)		0.6	0.9	0.7	0.8
Weighted average number of common shares outstanding - diluted under treasury stock	[2]	194.8	198.4	195.3	198.0
Diluted net earnings per common share (in dollars per share)	[2]	$ 0.45	$ 0.25	$ 0.23	$ 0.76

[1] Due to changes in the accounting treatment of a factoring agreement the Company reclassified amounts from cash and cash equivalents to other receivables of $7.8 million as of June 30, 2016. This reclassification resulted in an increase in cash provided by operating activities of $1.1 million for the six months ended June 30, 2016.

[2] The Company early adopted ASU 2016-09 on a prospective basis as required, related to the recognition of excess tax benefits to the income statement which were previously recorded in additional paid-in capital, effective January 1, 2016. This resulted in an additional 456,352 and 436,288 diluted weighted average number of common shares outstanding for the three and six months ended June 30, 2016, respectively, and recognition of excess tax benefits of $9.6 million in net earnings from continuing operations and $1.0 million in net earnings from discontinued operations for the six months ended June 30, 2016 (there was no impact for the three months ended June 30, 2016). As a result, net earnings per common share increased by $0.05 per share for the six months ended June 30, 2016 and no impact for the three months ended June 30, 2016. Refer to Note 2, “Recently Issued Accounting Standards” of the Notes to the Condensed Consolidated Financial Statements for further details.