Significant Transactions (Details) ₪ in Millions, $ in Millions	1 Months Ended		2 Months Ended				3 Months Ended					6 Months Ended
	Jan. 31, 2014 USD ($)	Oct. 31, 2011 USD ($)	Feb. 23, 2015 ILS (₪)	Feb. 23, 2015 USD ($)	Feb. 19, 2014 ILS (₪) business	Feb. 19, 2014 USD ($) business	Jun. 30, 2015 ILS (₪)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2015 USD ($)	Oct. 10, 2014 USD ($)	Mar. 14, 2014 USD ($)	Dec. 31, 2013 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates												$ 2.4	$ 32.2
Assets								$ 10,429.3	$ 10,455.7			10,429.3
Goodwill								169.2	168.9	$ 23.8	$ 23.8	169.2	23.8	$ 169.2			$ 0.0
Intangible Assets, Net (Excluding Goodwill)								186.4	197.5	59.8	62.4	186.4	59.8	$ 193.4			$ 20.7
Goodwill and intangible assets								355.6	366.4			355.6
Liabilities								5,970.8	5,917.3			5,970.8
Payments to Acquire Additional Interest in Subsidiaries												9.1	0.0
Net Income (Loss) Attributable to Noncontrolling Interest								$ 0.9		(4.6)		$ 8.2	(4.0)
Tranzact [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Interest in Subsidiaries and Affiliates		$ 177.7
Enterprise Value of Subsidiary															$ 281.2
Proceeds from Contributions from Affiliates									44.2
Ownership interest (as a percent)															63.20%
Assets															$ 332.8
Tangible Assets															41.4
Goodwill															145.1
Intangible Assets, Net (Excluding Goodwill)															146.3
Liabilities															$ 108.7
PPCI Global Ltd. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share								50				50
Payments to Acquire Interest in Subsidiaries and Affiliates								$ 21.0
OneTitle [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Agreed Upon Commitment of Contributed Capital								13.0				$ 13.0
Star & Shield Insurance Exchange
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase of Surplus Notes								20.0				20.0
Assets								13.4	13.5			13.4
Liabilities								27.8	25.9			27.8
QuoteLab
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business Combination, Contingent Consideration, Liability								$ 7.9	$ 7.9			$ 7.9
Payments to Acquire Businesses and Interest in Affiliates											$ 28.1
Percentage of gross profit																62.50%
Assets																$ 70.1
Goodwill																18.3
Goodwill and intangible assets																38.5
Liabilities																$ 10.0
WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Premiums Written, Percentage of Total					85.00%	85.00%
Number of lines of business | business					4	4
Goodwill						$ 5.5
Liabilities						$ 0.7
Star & Shield LLC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates	$ 1.8
Common Class A | QuoteLab
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest (as a percent)																60.00%
Common Stock | Cashboard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest (as a percent)				56.20%				68.30%				68.30%
Common Stock | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest (as a percent)						54.00%		95.30%				95.30%
Non-controlling interest | Star & Shield Insurance Exchange
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interest								$ 0.8		$ 5.2		$ 1.9	$ 9.7
Israel, New Shekels
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Interest in Subsidiaries and Affiliates | ₪							₪ 10.0
Israel, New Shekels | Convertible Preferred Stock [Member] | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Additional Interest in Subsidiaries | ₪							25.0
Israel, New Shekels | Common Stock | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Additional Interest in Subsidiaries | ₪							₪ 35.0
Israel, New Shekels | Preferred Stock [Member] | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates | ₪					₪ 31.5
Israel, New Shekels | Common Stock | Cashboard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates | ₪			₪ 9.5
Israel, New Shekels | Common Stock | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates | ₪					₪ 14.4
United States of America, Dollars
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Interest in Subsidiaries and Affiliates								2.6
United States of America, Dollars | Convertible Preferred Stock [Member] | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Additional Interest in Subsidiaries								6.6
United States of America, Dollars | Common Stock | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Additional Interest in Subsidiaries								$ 9.1
United States of America, Dollars | Preferred Stock [Member] | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates						$ 8.5
United States of America, Dollars | Common Stock | Cashboard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates				$ 2.4
United States of America, Dollars | Common Stock | WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Businesses and Interest in Affiliates						4.1
Cashboard [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets				5.5
Goodwill				0.3
Intangible Assets, Net (Excluding Goodwill)				2.8
Liabilities				$ 1.2
WOBI
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets						13.4
Intangible Assets, Net (Excluding Goodwill)						$ 2.9