Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Consolidated Statements OF Comprehensive Income [Abstract]
Net income	$ 35,400	$ 71,626	$ 47,723	$ 124,115
Pension settlement costs, net of tax (see Notes 15 and 16)	24,992		24,992
Other comprehensive income, net of tax (see Note 15)	6,313	2,308	19,805	12,142
Comprehensive income	66,705	73,934	92,520	136,257
Less: Income attributable to the noncontrolling interest in a partnership		(4,626)	(2,643)	(12,358)
Comprehensive income attributable to the common shareholders of Frontier	$ 66,705	$ 69,308	$ 89,877	$ 123,899