Fair Value Measurements - Carrying Value and Estimated Fair Values of Outstanding Debt (Detail) (USD $) In Millions, unless otherwise specified	Apr. 04, 2015	Jan. 03, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes, carrying value	$ 1,544.2	$ 1,555.6
6.750% Senior Notes Due in 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes, carrying value	625.0	625.0
10.000% Senior Notes Due in 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes, carrying value	394.2	405.6
5.375% Senior Notes Due in 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes, carrying value	525.0	525.0
Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Outstanding debt, fair value	1,560.4	1,515.2
Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | 6.750% Senior Notes Due in 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Outstanding debt, fair value	646.9	630.1
Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | 10.000% Senior Notes Due in 2021 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Outstanding debt, fair value	409.5	403.4
Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | 5.375% Senior Notes Due in 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Outstanding debt, fair value	$ 504.0	$ 481.7