Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	$ (27,745,000)	$ (55,300,000)	$ (26,500,000)
Other comprehensive income (loss), before reclassifications	(19,100,000)	24,300,000	3,800,000
Amounts reclassified from accumulated other comprehensive income (loss)	(12,700,000)	3,300,000	(32,600,000)
Net current period other comprehensive income (loss)	(31,743,000)	(27,560,000)	(28,705,000)
Accumulated other comprehensive income (loss), net of tax ending balance	(59,488,000)	(27,745,000)	(55,300,000)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	5,600,000	4,200,000	0
Other comprehensive income (loss), before reclassifications	400,000	11,800,000	5,100,000
Amounts reclassified from accumulated other comprehensive income (loss)	(6,400,000)	(10,400,000)	(900,000)
Net current period other comprehensive income (loss)	6,000,000	(1,400,000)	(4,200,000)
Accumulated other comprehensive income (loss), net of tax ending balance	(400,000)	5,600,000	4,200,000
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	(23,700,000)	(10,700,000)	32,800,000
Other comprehensive income (loss), before reclassifications	101,700,000	(26,700,000)	(11,800,000)
Amounts reclassified from accumulated other comprehensive income (loss)	(6,300,000)	13,700,000	(31,700,000)
Net current period other comprehensive income (loss)	(95,400,000)	13,000,000	43,500,000
Accumulated other comprehensive income (loss), net of tax ending balance	71,700,000	(23,700,000)	(10,700,000)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	(19,600,000)	(21,700,000)	(9,000,000)
Other comprehensive income (loss), before reclassifications	(12,000,000)	2,100,000	(12,700,000)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0
Net current period other comprehensive income (loss)	12,000,000	(2,100,000)	12,700,000
Accumulated other comprehensive income (loss), net of tax ending balance	(31,600,000)	(19,600,000)	(21,700,000)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax beginning balance	10,000,000	(27,100,000)	(50,300,000)
Other comprehensive income (loss), before reclassifications	(109,200,000)	37,100,000	23,200,000
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0
Net current period other comprehensive income (loss)	109,200,000	(37,100,000)	(23,200,000)
Accumulated other comprehensive income (loss), net of tax ending balance	$ (99,200,000)	$ 10,000,000	$ (27,100,000)