Net Income Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net income used for basic and diluted earnings per common share [Abstract]
Net income attributable to common shareholders of Frontier	$ 26,768	$ 54,711
Less: Dividends paid on unvested restricted stock awards	(737)	(966)
Total basic and diluted net income attributable to common shareholders of Frontier	$ 26,031	$ 53,745
Basic earnings per common share [Abstract]
Total weighted average shares and unvested restricted stock awards outstanding - basic (in shares)	995,897,000	994,547,000
Less: Weighted average unvested restricted stock awards (in shares)	(7,024,000)	(4,798,000)
Total weighted average shares outstanding - basic (in shares)	988,873,000	989,749,000
Net income per share attributable to common shareholders of Frontier (in dollars per share)	$ 0.03	$ 0.05
Diluted earnings per common share [Abstract]
Total weighted average shares outstanding - basic (in shares)	988,873,000	989,749,000
Effect of dilutive shares (in shares)	12,000	1,213,000
Effect of dilutive stock units (in shares)	623,000	474,000
Total weighted average shares outstanding - diluted (in shares)	989,508,000	991,436,000
Net income per share attributable to common shareholders of Frontier (in dollars per share)	$ 0.03	$ 0.05
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)	895,000	1,115,000
Exercise price range of stock options related to employee compensation plans - lower range limit (in dollars per share)	$ 8.19	$ 10.44
Exercise price range of stock options related to employee compensation plans - upper range limit (in dollars per share)	$ 14.15	$ 14.15
Non-Employee Directors' Deferred Fee Plan and Equity Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted earnings per share (in shares)	623,121	473,940