Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Accumulated other comprehensive income [Line Items]
Accumulated other comprehensive income (loss), net of tax	$ (70,538,000)	$ (22,400,000)	$ (59,488,000)	$ (27,700,000)
Other comprehensive income loss before reclassifications	23,700,000	1,200,000
Amounts reclassified from accumulated other comprehensive income loss	(34,700,000)	4,200,000
Net current period other comprehensive income loss	(11,050,000)	5,389,000
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated other comprehensive income [Line Items]
Accumulated other comprehensive income (loss), net of tax	900,000	7,300,000	(400,000)	5,600,000
Other comprehensive income loss before reclassifications	1,200,000	1,800,000
Amounts reclassified from accumulated other comprehensive income loss	100,000	(100,000)
Net current period other comprehensive income loss	1,300,000	1,700,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated other comprehensive income [Line Items]
Accumulated other comprehensive income (loss), net of tax	159,000,000	(17,900,000)	71,700,000	(23,700,000)
Other comprehensive income loss before reclassifications	122,100,000	1,500,000
Amounts reclassified from accumulated other comprehensive income loss	(34,800,000)	4,300,000
Net current period other comprehensive income loss	87,300,000	5,800,000
Accumulated Defined Benefit Plans Adjustment
Accumulated other comprehensive income [Line Items]
Accumulated other comprehensive income (loss), net of tax	(30,300,000)	(18,800,000)	(31,600,000)	(19,600,000)
Other comprehensive income loss before reclassifications	1,300,000	800,000
Amounts reclassified from accumulated other comprehensive income loss	0	0
Net current period other comprehensive income loss	1,300,000	800,000
Accumulated Translation Adjustment
Accumulated other comprehensive income [Line Items]
Accumulated other comprehensive income (loss), net of tax	(200,100,000)	7,100,000	(99,200,000)	10,000,000
Other comprehensive income loss before reclassifications	(100,900,000)	(2,900,000)
Amounts reclassified from accumulated other comprehensive income loss	0	0
Net current period other comprehensive income loss	$ (100,900,000)	$ (2,900,000)