Severance Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Notes To Consolidated Financial Statements [Abstract]
Description Of Postemployment Benefits		Severance Benefits NU recorded severance benefit expenses of $1.4 million and $5.7 million associated with the partial outsourcing of information technology functions and ongoing post-merger integration for the three and six months ended June 30, 2014, respectively. As of June 30, 2014 and December 31, 2013, the severance accrual totaled $9.3 million and $14.7 million, respectively, and was included in Other Current Liabilities on the balance sheets.
Postemployment Benefits Period Expense	$ 1.4	$ 5.7
Postemployment Benefits Liability Current And Noncurrent	$ 9.3	$ 9.3	$ 14.7