Income Taxes - Summary of Income Tax Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, opening balance	$ 2,776,000	$ 3,113,000	$ 2,952,000
Gross increases in tax positions taken in a prior year	107,000	83,000	347,000
Gross increases in tax positions taken in the current year	236,000	260,000	865,000
Settlements with taxing authorities	0	0	(507,000)
Lapse of applicable statute of limitations	(990,000)	(680,000)	(544,000)
Unrecognized tax benefits, ending balance	$ 2,129,000	$ 2,776,000	$ 3,113,000