Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2015

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Change in Benefit Obligation

The funded status and amounts recognized in the 2015 and 2014 consolidated balance sheets, as measured on December 31, 2015 and 2014, respectively, for the Pension and Postretirement Plans were as follows.

	Pension Plan			Postretirement Plan			Pension Plan			Postretirement Plan
	2015			2015			2014			2014
	($ in Thousands)
Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of year	$	303,496		$	—		$	282,000		$	—
Actual return on plan assets	495			—			15,255			—
Employer contributions	—			264			21,000			343
Gross benefits paid	(14,392		)	(264		)	(14,759		)	(343		)
Fair value of plan assets at end of year*	$	289,599		$	—		$	303,496		$	—
Change in Benefit Obligation
Net benefit obligation at beginning of year	$	171,333		$	3,578		$	154,624		$	3,288
Service cost	11,257			—			11,058			—
Interest cost	6,617			141			7,132			150
Actuarial (gain) loss	(3,032		)	(19		)	13,278			483
Gross benefits paid	(14,392		)	(264		)	(14,759		)	(343		)
Net benefit obligation at end of year*	$	171,783		$	3,436		$	171,333		$	3,578
Funded (unfunded) status	$	117,816		$	(3,436	)	$	132,163		$	(3,578	)
Noncurrent assets	117,816			—			132,163			—
Current liabilities	—			(274		)	—			(330		)
Noncurrent liabilities	—			(3,162		)	—			(3,248		)
Asset (Liability) Recognized in the Consolidated Balance Sheets	$	117,816		$	(3,436	)	$	132,163		$	(3,578	)

* The fair value of the plan assets represented 169% and 177% of the net benefit obligation of the pension plan at December 31, 2015 and 2014, respectively.

AOCI Components

Amounts recognized in accumulated other comprehensive loss, net of tax, as of December 31, 2015 and 2014 follow.

	Pension Plan		Postretirement Plan		Pension Plan		Postretirement Plan
	2015		2015		2014		2014
	($ in Thousands)
Prior service cost	$	122	$	—	$	153	$	—
Net actuarial loss	32,879		73		23,124		84
Amount not yet recognized in net periodic benefit cost, but recognized in accumulated other comprehensive loss	$	33,001	$	73	$	23,277	$	84

Changes in OCI

Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss) (“OCI”), net of tax, in 2015 and 2014 were as follows.

	Pension Plan 2015			Postretirement Plan 2015			Pension Plan 2014			Postretirement Plan 2014
	($ in Thousands)
Net gain (loss)	$	(17,911	)	$	19		$	(17,945	)	$	(483	)
Amortization of prior service cost	50			—			58			—
Amortization of actuarial gain (loss)	2,256			—			1,384			(35		)
Income tax (expense) benefit	5,880			(7		)	6,308			199
Total Recognized in OCI	$	(9,725	)	$	12		$	(10,195	)	$	(319	)

Net period benefit cost for the pension and postretirement plans

The components of net periodic benefit cost for the Pension and Postretirement Plans for 2015, 2014, and 2013 were as follows.

	Pension Plan 2015			Postretirement Plan 2015		Pension Plan 2014			Postretirement Plan 2014			Pension Plan 2013			Postretirement Plan 2013
						($ in Thousands)
Service cost	$	11,257		$	—	$	11,058		$	—		$	12,078		$	—
Interest cost	6,617			141		7,132			150			6,237			142
Expected return on plan assets	(21,438		)	—		(19,922		)	—			(17,647		)	—
Amortization of:
Prior service cost	50			—		58			—			72			—
Actuarial (gain) loss	2,256			—		1,384			(35		)	4,344			—
Total net pension cost	$	(1,258	)	$	141	$	(290	)	$	115		$	5,084		$	142

Weighted Average Benefit Assumptions

	Pension Plan 2015		Postretirement Plan 2015		Pension Plan 2014		Postretirement Plan 2014
Weighted average assumptions used to determine benefit obligations:
Discount rate	4.30	%	4.30	%	4.00	%	4.00	%
Rate of increase in compensation levels	4.00		NA		4.00		NA
Weighted average assumptions used to determine net periodic benefit costs:
Discount rate	4.00	%	4.00	%	4.80	%	4.80	%
Rate of increase in compensation levels	4.00		NA		4.00		NA
Expected long-term rate of return on plan assets	7.50		NA		7.50		NA

Plan Asset Allocation Percentages

The asset allocation for the Pension Plan as of the December 31, 2015 and 2014 measurement dates, respectively, by asset category were as follows.

Asset Category	2015		2014
Equity securities	60	%	64	%
Fixed income securities	40	%	35	%
Other	—	%	1	%
Total	100	%	100	%

Pension Plan Investments

Based on these inputs, the following table summarizes the fair value of the Pension Plan’s investments as of December 31, 2015 and 2014.

			Fair Value Measurements Using
	December 31, 2015		Level 1		Level 2		Level 3
	($ in Thousands)
Pension Plan Investments:
Money market account	$	481	$	481	$	—	$	—
Mutual funds	168,982		168,982		—		—
Common /collective trust funds	120,136		—		120,136		—
Total Pension Plan Investments	$	289,599	$	169,463	$	120,136	$	—
			Fair Value Measurements Using
	December 31, 2014		Level 1		Level 2		Level 3
	($ in Thousands)
Pension Plan Investments:
Money market account	$	2,868	$	2,868	$	—	$	—
Mutual funds	185,483		185,483		—		—
Common /collective trust funds	115,145		—		115,145		—
Total Pension Plan Investments	$	303,496	$	188,351	$	115,145	$	—

Expected Benefit Payments

The projected benefit payments for the Pension and Postretirement Plans at December 31, 2015, reflecting expected future services, were as follows. The projected benefit payments were calculated using the same assumptions as those used to calculate the benefit obligations listed above.

	Pension Plan		Postretirement Plan
	($ in Thousands)
Estimated future benefit payments:
2016	$	14,218	$	274
2017	13,885		257
2018	12,825		263
2019	12,580		250
2020	12,767		247
2021-2025	66,722		1,189

One Percentage Point Change in Assumed Health Care Cost

A one percentage point change in the assumed health care cost trend rate would have the following effect.

	2015					2014
	100 bp Increase		100 bp Decrease			100 bp Increase		100 bp Decrease
	($ in Thousands)
Effect on total of service and interest cost	$	15	$	(13	)	$	13	$	(11	)
Effect on postretirement benefit obligation	$	357	$	(310	)	$	316	$	(277	)