Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0001575879 (http://www.sec.gov/CIK)

Income Tax Disclosure [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Income Tax Disclosure [Abstract]
Provision for income taxes	The components of income before income taxes and the related provision for U.S. and other income taxes were as follows:   Year Ended December 31, (In millions) 2016   2015   2014 Income before income taxes           United States $ 790.6   $ 66.2   $ 54.0 Outside of the United States —   —   — Total income before income taxes $ 790.6   $ 66.2   $ 54.0   Year Ended December 31, (In millions) 2016   2015   2014 Provision for income taxes           Current           Federal $ 378.9   $ —   $ — State 3.1   —   — Deferred           Federal (207.8 )   34.2   38.4 State (2.7 )   —   1.0 Total provision for income taxes $ 171.5   $ 34.2   $ 39.4
Schedule of effective income tax rate reconciliation	The differences between the United States statutory federal income tax rate and the effective tax rate expressed as a percentage of income before taxes were as follows:   Year Ended December 31,   2016   2015   2014 Statutory tax rate 35.0  %   35.0  %   35.0  % Increases/(decreases) in tax resulting from:           State tax, net of federal tax benefit 0.2   0.1   1.2 Change in valuation allowance (11.0 )   16.7   36.5 Dividends received deduction (2.6 )   —   — Nondeductible expenses from CGP LLC 0.1   0.3   0.4 Federal tax credits from CGP LLC (0.1 )   (0.4 )   (0.5 ) Other 0.1   —   0.3 Effective tax rate 21.7  %   51.7  %   72.9  %
Schedule of deferred tax assets and liabilities	The major components of the Deferred tax assets and liabilities in our Balance Sheets were as follows:   December 31, (In millions) 2016   2015 Deferred tax assets       Federal net operating loss carryover $ —   $ 2.4 State net operating loss carryovers 0.6   1.4 Federal tax credit carryover —   0.8 Indirect tax benefits of state uncertain tax positions 1.0   — Compensation programs 2.3   2.1 Investment in CGP LLC 44.9   — Investment in notes from related party 91.1   89.6 Other 2.3   1.4 Total deferred tax assets 142.2   97.7 Less: valuation allowance (0.9 )   (87.7 )       Total deferred tax assets, less valuation allowance 141.3   10.0         Deferred tax liabilities       Investment in CGP LLC —   79.1 Prepaid expenses 0.7   0.8 Total deferred tax liabilities 0.7   79.9 Net deferred tax asset/(liability) $ 140.6   $ (69.9 )
Summary of tax uncertainties	Reserve amounts related to potential income tax liabilities resulting from uncertain tax positions were as follows: (In millions)   Balance at January 1, 2016 $ —   Additions for tax positions of current year 94.6   Additions for tax positions of prior years —   Reductions for tax positions of prior years —   Expiration of statutes — Balance at December 31, 2016 $ 94.6