Consolidated Statements of Equity (unaudited) - USD ($) $ in Millions	Total	Common Stock and Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance at Dec. 31, 2014	$ 369.0	$ 526.8	$ 292.1	$ (429.2)	$ (23.8)	$ 3.1
Increase (Decrease) in Stockholders' Equity
Net income	110.1		110.1
Repurchase of common stock	(108.7)			(108.7)
Stock based compensation	4.3	4.3
Exercise of stock options	21.8	(40.2)		62.0
Shares issued	0.9	0.9	0.0	0.0	0.0	0.0
Other comprehensive income (loss)	$ (12.3)				(13.0)	0.7
Dividends declared, per share	$ (0.00)
Ending balance at Jun. 30, 2015	$ 385.1	491.8	402.2	(475.9)	(36.8)	3.8
Beginning balance at Dec. 31, 2015	212.5	496.7	436.3	(658.4)	(66.8)	4.7
Increase (Decrease) in Stockholders' Equity
Net income	38.8		39.2			(0.4)
Repurchase of common stock	(35.1)			(35.1)
Stock based compensation	6.5	6.5
Exercise of stock options	19.3	(10.5)		29.8
Tax benefit related to stock plans	72.3	0.0	72.3	0.0	0.0	0.0
Shares issued	0.7	0.7	0.0	0.0	0.0	0.0
Other comprehensive income (loss)	(5.5)				(8.1)	2.6
Cash dividends declared ($0.17 per share)	$ 12.0		12.0
Dividends declared, per share	$ (0.17)
Distribution of GCP	$ 191.5		59.9		135.3	(3.7)
Ending balance at Jun. 30, 2016	$ 489.0	$ 493.4	$ 595.7	$ (663.7)	$ 60.4	$ 3.2