Quarterly Financial Data (Unaudited) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Quarterly Financial Data (Unaudited) [Abstract]
Revenue	$ 1,283,152,000	$ 1,290,939,000	$ 1,322,255,000	$ 1,346,697,000	$ 1,358,721,000	$ 1,402,968,000	$ 516,137,000	$ 519,849,000	$ 5,243,043,000	$ 3,797,675,000	$ 2,117,894,000
Operating income	230,457,000	180,291,000	238,280,000	250,593,000	239,680,000	234,045,000	136,411,000	161,862,000	899,621,000	771,998,000	606,165,000
Net income attributable to common shareholders of Frontier	42,247,000	20,395,000	32,261,000	54,711,000	45,992,000	28,995,000	35,121,000	42,565,000	149,614,000	152,673,000	120,783,000
Basic and diluted net income per common share attributable to common shareholders of Frontier (in dollars per share)	$ 0.04	$ 0.02	$ 0.03	$ 0.05	$ 0.05	$ 0.03	$ 0.11	$ 0.14	$ 0.15	$ 0.23	$ 0.38
Acquisition of the Acquired Business (in shares)					678.5	678.5
Acquisition and integration costs, before tax	42,200,000	67,400,000	20,300,000	13,200,000	11,300,000	78,500,000	37,000,000	10,400,000	143,146,000	137,142,000	28,334,000
Acquisition and integration costs, after tax	$ 26,100,000	$ 41,600,000	$ 12,600,000	$ 8,200,000	$ 7,000,000	$ 49,100,000	$ 23,100,000	$ 6,500,000
Acquisition and integration costs, after tax effect on net income (in dollars per share)	$ 0.03	$ 0.04	$ 0.01	$ 0.01	$ 0.01	$ 0.05	$ 0.08	$ 0.02